251033055240 has 128 divisors (see below), whose sum is σ = 829241349120. Its totient is φ = 60287712000.

The previous prime is 251033055233. The next prime is 251033055263. The reversal of 251033055240 is 42550330152.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 251033055198 and 251033055207.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 747436 + ... + 1029915.

It is an arithmetic number, because the mean of its divisors is an integer number (6478448040).

Almost surely, 2^251033055240 is an apocalyptic number.

251033055240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251033055240 is an abundant number, since it is smaller than the sum of its proper divisors (578208293880).

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

251033055240 is a wasteful number, since it uses less digits than its factorization.

251033055240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1777483 (or 1777479 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 30.

Adding to 251033055240 its reverse (42550330152), we get a palindrome (293583385392).

The spelling of 251033055240 in words is "two hundred fifty-one billion, thirty-three million, fifty-five thousand, two hundred forty".