61139011920 has 320 divisors, whose sum is σ = 220391608320. Its totient is φ = 13732614144.

The previous prime is 61139011909. The next prime is 61139011937. The reversal of 61139011920 is 2911093116.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23705191 + ... + 23707769.

It is an arithmetic number, because the mean of its divisors is an integer number (688723776).

Almost surely, 2^61139011920 is an apocalyptic number.

61139011920 is a gapful number since it is divisible by the number (60) 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 61139011920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110195804160).

61139011920 is an abundant number, since it is smaller than the sum of its proper divisors (159252596400).

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

61139011920 is a wasteful number, since it uses less digits than its factorization.

61139011920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2842 (or 2836 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 33.

The spelling of 61139011920 in words is "sixty-one billion, one hundred thirty-nine million, eleven thousand, nine hundred twenty".