645066664 has 16 divisors (see below), whose sum is σ = 1319454720. Its totient is φ = 293212080.

The previous prime is 645066661. The next prime is 645066673. The reversal of 645066664 is 466660546.

It is a super-2 number, since 2×645066664² = 832222002008177792, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 645066664.

It is not an unprimeable number, because it can be changed into a prime (645066661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3665064 + ... + 3665239.

It is an arithmetic number, because the mean of its divisors is an integer number (82465920).

Almost surely, 2^645066664 is an apocalyptic number.

It is an amenable number.

645066664 is an abundant number, since it is smaller than the sum of its proper divisors (674388056).

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

645066664 is a wasteful number, since it uses less digits than its factorization.

645066664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7330320 (or 7330316 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 43.

The square root of 645066664 is about 25398.1626107087. The cubic root of 645066664 is about 864.0420254192.

It can be divided in two parts, 645066 and 664, that multiplied together give a palindrome (428323824).

The spelling of 645066664 in words is "six hundred forty-five million, sixty-six thousand, six hundred sixty-four".