251161065 has 48 divisors (see below), whose sum is σ = 447999552. Its totient is φ = 130096512.

The previous prime is 251161049. The next prime is 251161093. The reversal of 251161065 is 560161152.

It is a happy number.

It is not a de Polignac number, because 251161065 - 2⁴ = 251161049 is a prime.

It is a Curzon number.

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 47 ways as a sum of consecutive naturals, for example, 566734 + ... + 567176.

It is an arithmetic number, because the mean of its divisors is an integer number (9333324).

Almost surely, 2^251161065 is an apocalyptic number.

It is an amenable number.

251161065 is a deficient number, since it is larger than the sum of its proper divisors (196838487).

251161065 is a wasteful number, since it uses less digits than its factorization.

251161065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790 (or 787 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 251161065 is about 15848.0618688848. The cubic root of 251161065 is about 630.9342525740.

The spelling of 251161065 in words is "two hundred fifty-one million, one hundred sixty-one thousand, sixty-five".