5661137664 has 648 divisors, whose sum is σ = 21162365952. Its totient is φ = 1423319040.

The previous prime is 5661137653. The next prime is 5661137759. The reversal of 5661137664 is 4667311665.

5661137664 is a `hidden beast` number, since 566 + 1 + 13 + 76 + 6 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 84494559 + ... + 84494625.

Almost surely, 2^5661137664 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 5661137664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10581182976).

5661137664 is an abundant number, since it is smaller than the sum of its proper divisors (15501228288).

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

5661137664 is a wasteful number, since it uses less digits than its factorization.

5661137664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153 (or 123 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 5661137664 is about 75240.5320555351. The cubic root of 5661137664 is about 1782.2470531573.

The spelling of 5661137664 in words is "five billion, six hundred sixty-one million, one hundred thirty-seven thousand, six hundred sixty-four".