251005040 has 160 divisors (see below), whose sum is σ = 705329856. Its totient is φ = 81838080.

The previous prime is 251005037. The next prime is 251005087. The reversal of 251005040 is 40500152.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 422984 + ... + 423576.

Almost surely, 2^251005040 is an apocalyptic number.

251005040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251005040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (352664928).

251005040 is an abundant number, since it is smaller than the sum of its proper divisors (454324816).

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

251005040 is a wasteful number, since it uses less digits than its factorization.

251005040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667 (or 661 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 17.

The square root of 251005040 is about 15843.1385779460. The cubic root of 251005040 is about 630.8035769214.

Adding to 251005040 its reverse (40500152), we get a palindrome (291505192).

The spelling of 251005040 in words is "two hundred fifty-one million, five thousand, forty".