645350666 has 16 divisors (see below), whose sum is σ = 985074048. Its totient is φ = 317024400.

The previous prime is 645350663. The next prime is 645350681. The reversal of 645350666 is 666053546.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (645350663) 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, 33851 + ... + 49361.

It is an arithmetic number, because the mean of its divisors is an integer number (61567128).

Almost surely, 2^645350666 is an apocalyptic number.

645350666 is a deficient number, since it is larger than the sum of its proper divisors (339723382).

645350666 is a wasteful number, since it uses less digits than its factorization.

645350666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15877.

The product of its (nonzero) digits is 388800, while the sum is 41.

The square root of 645350666 is about 25403.7529904540. The cubic root of 645350666 is about 864.1688100724.

The spelling of 645350666 in words is "six hundred forty-five million, three hundred fifty thousand, six hundred sixty-six".