251984161 has 16 divisors (see below), whose sum is σ = 306250560. Its totient is φ = 204160320.

The previous prime is 251984147. The next prime is 251984179. The reversal of 251984161 is 161489152.

It is not a de Polignac number, because 251984161 - 2⁹ = 251983649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 251984161.

It is not an unprimeable number, because it can be changed into a prime (251984111) 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 15 ways as a sum of consecutive naturals, for example, 26235 + ... + 34528.

It is an arithmetic number, because the mean of its divisors is an integer number (19140660).

Almost surely, 2^251984161 is an apocalyptic number.

It is an amenable number.

251984161 is a deficient number, since it is larger than the sum of its proper divisors (54266399).

251984161 is a wasteful number, since it uses less digits than its factorization.

251984161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60816.

The product of its digits is 17280, while the sum is 37.

The square root of 251984161 is about 15874.0089769409. The cubic root of 251984161 is about 631.6227260466.

The spelling of 251984161 in words is "two hundred fifty-one million, nine hundred eighty-four thousand, one hundred sixty-one".