61137664 has 72 divisors (see below), whose sum is σ = 141199520. Its totient is φ = 25878528.

The previous prime is 61137641. The next prime is 61137679. The reversal of 61137664 is 46673116.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195172 + ... + 195484.

Almost surely, 2^61137664 is an apocalyptic number.

61137664 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 61137664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70599760).

61137664 is an abundant number, since it is smaller than the sum of its proper divisors (80061856).

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

61137664 is a wasteful number, since it uses less digits than its factorization.

61137664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445 (or 431 counting only the distinct ones).

The product of its digits is 18144, while the sum is 34.

The square root of 61137664 is about 7819.0577437438. The cubic root of 61137664 is about 393.9456236638.

The spelling of 61137664 in words is "sixty-one million, one hundred thirty-seven thousand, six hundred sixty-four".