251265555 has 24 divisors (see below), whose sum is σ = 445658928. Its totient is φ = 130890816.

The previous prime is 251265551. The next prime is 251265577. The reversal of 251265555 is 555562152.

It is not a de Polignac number, because 251265555 - 2² = 251265551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (251265551) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 62992 + ... + 66861.

It is an arithmetic number, because the mean of its divisors is an integer number (18569122).

Almost surely, 2^251265555 is an apocalyptic number.

251265555 is a deficient number, since it is larger than the sum of its proper divisors (194393373).

251265555 is a wasteful number, since it uses less digits than its factorization.

251265555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129907 (or 129904 counting only the distinct ones).

The product of its digits is 75000, while the sum is 36.

The square root of 251265555 is about 15851.3581437049. The cubic root of 251265555 is about 631.0217358520.

The spelling of 251265555 in words is "two hundred fifty-one million, two hundred sixty-five thousand, five hundred fifty-five".