6631537664 has 44 divisors (see below), whose sum is σ = 13361243904. Its totient is φ = 3289595904.

The previous prime is 6631537657. The next prime is 6631537687. The reversal of 6631537664 is 4667351366.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104552 + ... + 155544.

Almost surely, 2^6631537664 is an apocalyptic number.

6631537664 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 6631537664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6680621952).

6631537664 is an abundant number, since it is smaller than the sum of its proper divisors (6729706240).

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

6631537664 is a wasteful number, since it uses less digits than its factorization.

6631537664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51140 (or 51122 counting only the distinct ones).

The product of its digits is 1632960, while the sum is 47.

The square root of 6631537664 is about 81434.2536283105. The cubic root of 6631537664 is about 1878.7604685749.

The spelling of 6631537664 in words is "six billion, six hundred thirty-one million, five hundred thirty-seven thousand, six hundred sixty-four".