666256635 has 24 divisors (see below), whose sum is σ = 1259831664. Its totient is φ = 323033280.

The previous prime is 666256621. The next prime is 666256637. The reversal of 666256635 is 536652666.

It is not a de Polignac number, because 666256635 - 2¹⁵ = 666223867 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (666256637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 672492 + ... + 673481.

It is an arithmetic number, because the mean of its divisors is an integer number (52492986).

Almost surely, 2^666256635 is an apocalyptic number.

666256635 is a deficient number, since it is larger than the sum of its proper divisors (593575029).

666256635 is a wasteful number, since it uses less digits than its factorization.

666256635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1345995 (or 1345992 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 45.

The square root of 666256635 is about 25811.9475243539. The cubic root of 666256635 is about 873.4013301789.

The spelling of 666256635 in words is "six hundred sixty-six million, two hundred fifty-six thousand, six hundred thirty-five".