61529912920 has 128 divisors (see below), whose sum is σ = 161092800000. Its totient is φ = 20713761792.

The previous prime is 61529912849. The next prime is 61529912929. The reversal of 61529912920 is 2921992516.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61529912929) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18649431 + ... + 18652729.

It is an arithmetic number, because the mean of its divisors is an integer number (1258537500).

Almost surely, 2^61529912920 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 61529912920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80546400000).

61529912920 is an abundant number, since it is smaller than the sum of its proper divisors (99562887080).

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

61529912920 is a wasteful number, since it uses less digits than its factorization.

61529912920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4505 (or 4501 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 46.

The spelling of 61529912920 in words is "sixty-one billion, five hundred twenty-nine million, nine hundred twelve thousand, nine hundred twenty".