664556958 has 72 divisors (see below), whose sum is σ = 1636748568. Its totient is φ = 193692384.

The previous prime is 664556941. The next prime is 664556969. The reversal of 664556958 is 859655466.

It is a congruent number.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 80541 + ... + 88407.

It is an arithmetic number, because the mean of its divisors is an integer number (22732619).

Almost surely, 2^664556958 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664556958, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (818374284).

664556958 is an abundant number, since it is smaller than the sum of its proper divisors (972191610).

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

664556958 is a wasteful number, since it uses less digits than its factorization.

664556958 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7926 (or 7904 counting only the distinct ones).

The product of its digits is 7776000, while the sum is 54.

The square root of 664556958 is about 25779.0022692889. The cubic root of 664556958 is about 872.6579908366.

The spelling of 664556958 in words is "six hundred sixty-four million, five hundred fifty-six thousand, nine hundred fifty-eight".