61601664 has 64 divisors (see below), whose sum is σ = 166464000. Its totient is φ = 20178432.

The previous prime is 61601621. The next prime is 61601711. The reversal of 61601664 is 46610616.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

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, 21297 + ... + 24015.

It is an arithmetic number, because the mean of its divisors is an integer number (2601000).

Almost surely, 2^61601664 is an apocalyptic number.

61601664 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 61601664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83232000).

61601664 is an abundant number, since it is smaller than the sum of its proper divisors (104862336).

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

61601664 is a wasteful number, since it uses less digits than its factorization.

61601664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2795 (or 2783 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 61601664 is about 7848.6727540394. The cubic root of 61601664 is about 394.9397205456.

The spelling of 61601664 in words is "sixty-one million, six hundred one thousand, six hundred sixty-four".