666135620 has 12 divisors (see below), whose sum is σ = 1398884844. Its totient is φ = 266454240.

The previous prime is 666135619. The next prime is 666135623. The reversal of 666135620 is 26531666.

It can be written as a sum of positive squares in 2 ways, for example, as 509585476 + 156550144 = 22574^2 + 12512^2 .

It is not an unprimeable number, because it can be changed into a prime (666135623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16653371 + ... + 16653410.

It is an arithmetic number, because the mean of its divisors is an integer number (116573737).

Almost surely, 2^666135620 is an apocalyptic number.

It is an amenable number.

666135620 is an abundant number, since it is smaller than the sum of its proper divisors (732749224).

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

666135620 is a wasteful number, since it uses less digits than its factorization.

666135620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33306790 (or 33306788 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 666135620 is about 25809.6032515031. The cubic root of 666135620 is about 873.3484471224.

The spelling of 666135620 in words is "six hundred sixty-six million, one hundred thirty-five thousand, six hundred twenty".