664969368 has 64 divisors (see below), whose sum is σ = 1906248960. Its totient is φ = 189357696.

The previous prime is 664969343. The next prime is 664969379. The reversal of 664969368 is 863969466.

It is a Cunningham number, because it is equal to 25787²-1.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45130 + ... + 58022.

It is an arithmetic number, because the mean of its divisors is an integer number (29785140).

Almost surely, 2^664969368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664969368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (953124480).

664969368 is an abundant number, since it is smaller than the sum of its proper divisors (1241279592).

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

664969368 is a wasteful number, since it uses less digits than its factorization.

664969368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13216 (or 13212 counting only the distinct ones).

The product of its digits is 10077696, while the sum is 57.

The square root of 664969368 is about 25786.9999806104. Note that the first 4 decimals coincide. The cubic root of 664969368 is about 872.8384712083.

The spelling of 664969368 in words is "six hundred sixty-four million, nine hundred sixty-nine thousand, three hundred sixty-eight".