251466661 has 4 divisors (see below), whose sum is σ = 252423072. Its totient is φ = 250510252.

The previous prime is 251466643. The next prime is 251466671. The reversal of 251466661 is 166664152.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 251466661 - 2¹⁷ = 251335589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 251466661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251466641) 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 3 ways as a sum of consecutive naturals, for example, 477811 + ... + 478336.

It is an arithmetic number, because the mean of its divisors is an integer number (63105768).

Almost surely, 2^251466661 is an apocalyptic number.

It is an amenable number.

251466661 is a deficient number, since it is larger than the sum of its proper divisors (956411).

251466661 is an equidigital number, since it uses as much as digits as its factorization.

251466661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 956410.

The product of its digits is 51840, while the sum is 37.

The square root of 251466661 is about 15857.7003692213. The cubic root of 251466661 is about 631.1900417384.

The spelling of 251466661 in words is "two hundred fifty-one million, four hundred sixty-six thousand, six hundred sixty-one".