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251025140 = 22512551257
BaseRepresentation
bin11101111011001…
…01011011110100
3122111100101202102
432331211123310
51003230301030
640524201232
76135451502
oct1675453364
9574311672
10251025140
111197739a3
1270099218
13400111b2
14254a5672
1517087c45
hexef656f4

251025140 has 12 divisors (see below), whose sum is σ = 527152836. Its totient is φ = 100410048.

The previous prime is 251025133. The next prime is 251025143. The reversal of 251025140 is 41520152.

It can be written as a sum of positive squares in 2 ways, for example, as 187854436 + 63170704 = 13706^2 + 7948^2 .

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 12551257 = 251025140 / (2 + 5 + 1 + 0 + 2 + 5 + 1 + 4 + 0).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251025143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6275609 + ... + 6275648.

It is an arithmetic number, because the mean of its divisors is an integer number (43929403).

Almost surely, 2251025140 is an apocalyptic number.

251025140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251025140 is an abundant number, since it is smaller than the sum of its proper divisors (276127696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251025140 is a wasteful number, since it uses less digits than its factorization.

251025140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12551266 (or 12551264 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 251025140 is about 15843.7729092537. The cubic root of 251025140 is about 630.8204143170.

Adding to 251025140 its reverse (41520152), we get a palindrome (292545292).

The spelling of 251025140 in words is "two hundred fifty-one million, twenty-five thousand, one hundred forty".

Divisors: 1 2 4 5 10 20 12551257 25102514 50205028 62756285 125512570 251025140