61657931 has 2 divisors, whose sum is σ = 61657932. Its totient is φ = 61657930.

The previous prime is 61657909. The next prime is 61657943. The reversal of 61657931 is 13975616.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61657931 is a prime.

It is a super-2 number, since 2×61657931² = 7603400910401522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61657951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30828965 + 30828966.

It is an arithmetic number, because the mean of its divisors is an integer number (30828966).

Almost surely, 2^61657931 is an apocalyptic number.

61657931 is a deficient number, since it is larger than the sum of its proper divisors (1).

61657931 is an equidigital number, since it uses as much as digits as its factorization.

61657931 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 38.

The square root of 61657931 is about 7852.2564272953. The cubic root of 61657931 is about 395.0599300192.

The spelling of 61657931 in words is "sixty-one million, six hundred fifty-seven thousand, nine hundred thirty-one".