671537664 has 240 divisors, whose sum is σ = 2246999040. Its totient is φ = 189112320.

The previous prime is 671537651. The next prime is 671537707. The reversal of 671537664 is 466735176.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3515809 + ... + 3515999.

It is an arithmetic number, because the mean of its divisors is an integer number (9362496).

Almost surely, 2^671537664 is an apocalyptic number.

671537664 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 671537664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1123499520).

671537664 is an abundant number, since it is smaller than the sum of its proper divisors (1575461376).

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

671537664 is a wasteful number, since it uses less digits than its factorization.

671537664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331 (or 312 counting only the distinct ones).

The product of its digits is 635040, while the sum is 45.

The square root of 671537664 is about 25914.0437600927. The cubic root of 671537664 is about 875.7029079483.

The spelling of 671537664 in words is "six hundred seventy-one million, five hundred thirty-seven thousand, six hundred sixty-four".