664220544 has 256 divisors, whose sum is σ = 2056320000. Its totient is φ = 188227584.

The previous prime is 664220537. The next prime is 664220567. The reversal of 664220544 is 445022466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4457782 + ... + 4457930.

It is an arithmetic number, because the mean of its divisors is an integer number (8032500).

Almost surely, 2^664220544 is an apocalyptic number.

664220544 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664220544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1028160000).

664220544 is an abundant number, since it is smaller than the sum of its proper divisors (1392099456).

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

664220544 is a wasteful number, since it uses less digits than its factorization.

664220544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 33.

The square root of 664220544 is about 25772.4764817043. The cubic root of 664220544 is about 872.5107128073.

The spelling of 664220544 in words is "six hundred sixty-four million, two hundred twenty thousand, five hundred forty-four".