251279961 has 8 divisors (see below), whose sum is σ = 339281280. Its totient is φ = 165399312.

The previous prime is 251279929. The next prime is 251279993. The reversal of 251279961 is 169972152.

It is an interprime number because it is at equal distance from previous prime (251279929) and next prime (251279993).

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

It is not a de Polignac number, because 251279961 - 2⁵ = 251279929 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (251259961) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 529890 + ... + 530363.

It is an arithmetic number, because the mean of its divisors is an integer number (42410160).

Almost surely, 2^251279961 is an apocalyptic number.

It is an amenable number.

251279961 is a deficient number, since it is larger than the sum of its proper divisors (88001319).

251279961 is a wasteful number, since it uses less digits than its factorization.

251279961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060335.

The product of its digits is 68040, while the sum is 42.

The square root of 251279961 is about 15851.8125462043. The cubic root of 251279961 is about 631.0337952386.

The spelling of 251279961 in words is "two hundred fifty-one million, two hundred seventy-nine thousand, nine hundred sixty-one".