251978897 has 8 divisors (see below), whose sum is σ = 255024000. Its totient is φ = 248947344.

The previous prime is 251978887. The next prime is 251978899. The reversal of 251978897 is 798879152.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251978897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251978899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36854 + ... + 43152.

It is an arithmetic number, because the mean of its divisors is an integer number (31878000).

Almost surely, 2^251978897 is an apocalyptic number.

It is an amenable number.

251978897 is a deficient number, since it is larger than the sum of its proper divisors (3045103).

251978897 is a wasteful number, since it uses less digits than its factorization.

251978897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6775.

The product of its digits is 2540160, while the sum is 56.

The square root of 251978897 is about 15873.8431704487. The cubic root of 251978897 is about 631.6183277739.

The spelling of 251978897 in words is "two hundred fifty-one million, nine hundred seventy-eight thousand, eight hundred ninety-seven".