666440620 has 24 divisors (see below), whose sum is σ = 1400022288. Its totient is φ = 266481600.

The previous prime is 666440597. The next prime is 666440627. The reversal of 666440620 is 26044666.

It is not an unprimeable number, because it can be changed into a prime (666440627) 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, 88815 + ... + 96025.

It is an arithmetic number, because the mean of its divisors is an integer number (58334262).

Almost surely, 2^666440620 is an apocalyptic number.

It is an amenable number.

666440620 is an abundant number, since it is smaller than the sum of its proper divisors (733581668).

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

666440620 is a wasteful number, since it uses less digits than its factorization.

666440620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11841 (or 11839 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 666440620 is about 25815.5112287167. The cubic root of 666440620 is about 873.4817185988.

The spelling of 666440620 in words is "six hundred sixty-six million, four hundred forty thousand, six hundred twenty".