664169328 has 80 divisors (see below), whose sum is σ = 2018576160. Its totient is φ = 208364544.

The previous prime is 664169323. The next prime is 664169347. The reversal of 664169328 is 823961466.

It is a super-2 number, since 2×664169328² = 882241792511943168, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664169323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37875 + ... + 52562.

It is an arithmetic number, because the mean of its divisors is an integer number (25232202).

Almost surely, 2^664169328 is an apocalyptic number.

664169328 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

664169328 is an abundant number, since it is smaller than the sum of its proper divisors (1354406832).

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

664169328 is a wasteful number, since it uses less digits than its factorization.

664169328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90471 (or 90459 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 664169328 is about 25771.4828444155. The cubic root of 664169328 is about 872.4882866932.

The spelling of 664169328 in words is "six hundred sixty-four million, one hundred sixty-nine thousand, three hundred twenty-eight".