251796861 has 12 divisors (see below), whose sum is σ = 364552188. Its totient is φ = 167474304.

The previous prime is 251796859. The next prime is 251796899. The reversal of 251796861 is 168697152.

It can be written as a sum of positive squares in 2 ways, for example, as 48734361 + 203062500 = 6981^2 + 14250^2 .

It is not a de Polignac number, because 251796861 - 2¹ = 251796859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251796161) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28410 + ... + 36203.

It is an arithmetic number, because the mean of its divisors is an integer number (30379349).

Almost surely, 2^251796861 is an apocalyptic number.

It is an amenable number.

251796861 is a deficient number, since it is larger than the sum of its proper divisors (112755327).

251796861 is a wasteful number, since it uses less digits than its factorization.

251796861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65052 (or 65049 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 251796861 is about 15868.1082993531. The cubic root of 251796861 is about 631.4661920542.

The spelling of 251796861 in words is "two hundred fifty-one million, seven hundred ninety-six thousand, eight hundred sixty-one".