61315920 has 80 divisors (see below), whose sum is σ = 211206720. Its totient is φ = 16350336.

The previous prime is 61315909. The next prime is 61315949. The reversal of 61315920 is 2951316.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12034 + ... + 16353.

It is an arithmetic number, because the mean of its divisors is an integer number (2640084).

Almost surely, 2^61315920 is an apocalyptic number.

61315920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61315920 is an abundant number, since it is smaller than the sum of its proper divisors (149890800).

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

61315920 is a wasteful number, since it uses less digits than its factorization.

61315920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28409 (or 28397 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 61315920 is about 7830.4482630307. The cubic root of 61315920 is about 394.3281212827.

The spelling of 61315920 in words is "sixty-one million, three hundred fifteen thousand, nine hundred twenty".