664946780 has 24 divisors (see below), whose sum is σ = 1415519952. Its totient is φ = 262334592.

The previous prime is 664946773. The next prime is 664946791. The reversal of 664946780 is 87649466.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 226262 + ... + 229181.

It is an arithmetic number, because the mean of its divisors is an integer number (58979998).

Almost surely, 2^664946780 is an apocalyptic number.

It is an amenable number.

664946780 is an abundant number, since it is smaller than the sum of its proper divisors (750573172).

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

664946780 is a wasteful number, since it uses less digits than its factorization.

664946780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455525 (or 455523 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 50.

The square root of 664946780 is about 25786.5620042688. The cubic root of 664946780 is about 872.8285880971.

The spelling of 664946780 in words is "six hundred sixty-four million, nine hundred forty-six thousand, seven hundred eighty".