666942810 has 32 divisors (see below), whose sum is σ = 1694820672. Its totient is φ = 167389440.

The previous prime is 666942791. The next prime is 666942811. The reversal of 666942810 is 18249666.

It is a super-2 number, since 2×666942810² = 889625423621392200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666942811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 653356 + ... + 654375.

It is an arithmetic number, because the mean of its divisors is an integer number (52963146).

Almost surely, 2^666942810 is an apocalyptic number.

666942810 is an abundant number, since it is smaller than the sum of its proper divisors (1027877862).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666942810 is a wasteful number, since it uses less digits than its factorization.

666942810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1307758.

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 666942810 is about 25825.2359137337. The cubic root of 666942810 is about 873.7010647971.

The spelling of 666942810 in words is "six hundred sixty-six million, nine hundred forty-two thousand, eight hundred ten".