251264661 has 8 divisors (see below), whose sum is σ = 336077664. Its totient is φ = 166980720.

The previous prime is 251264659. The next prime is 251264701. The reversal of 251264661 is 166462152.

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

It is not a de Polignac number, because 251264661 - 2¹ = 251264659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251264621) 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, 131155 + ... + 133056.

It is an arithmetic number, because the mean of its divisors is an integer number (42009708).

Almost surely, 2^251264661 is an apocalyptic number.

It is an amenable number.

251264661 is a deficient number, since it is larger than the sum of its proper divisors (84813003).

251264661 is a wasteful number, since it uses less digits than its factorization.

251264661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264531.

The product of its digits is 17280, while the sum is 33.

The square root of 251264661 is about 15851.3299442034. The cubic root of 251264661 is about 631.0209874617.

The spelling of 251264661 in words is "two hundred fifty-one million, two hundred sixty-four thousand, six hundred sixty-one".