61520931 has 8 divisors (see below), whose sum is σ = 91142160. Its totient is φ = 41013936.

The previous prime is 61520923. The next prime is 61520971. The reversal of 61520931 is 13902516.

It is not a de Polignac number, because 61520931 - 2³ = 61520923 is a prime.

It is a super-2 number, since 2×61520931² = 7569649902213522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 2278553 = 61520931 / (6 + 1 + 5 + 2 + 0 + 9 + 3 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 61520895 and 61520904.

It is not an unprimeable number, because it can be changed into a prime (61520971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1139250 + ... + 1139303.

It is an arithmetic number, because the mean of its divisors is an integer number (11392770).

Almost surely, 2^61520931 is an apocalyptic number.

61520931 is a deficient number, since it is larger than the sum of its proper divisors (29621229).

61520931 is a wasteful number, since it uses less digits than its factorization.

61520931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2278562 (or 2278556 counting only the distinct ones).

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

The square root of 61520931 is about 7843.5279689691. The cubic root of 61520931 is about 394.7671136953.

The spelling of 61520931 in words is "sixty-one million, five hundred twenty thousand, nine hundred thirty-one".