61556431 has 2 divisors, whose sum is σ = 61556432. Its totient is φ = 61556430.

The previous prime is 61556399. The next prime is 61556459. The reversal of 61556431 is 13465516.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61556431 - 2⁵ = 61556399 is a prime.

It is a super-2 number, since 2×61556431² = 7578388394915522, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 61556393 and 61556402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61554431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30778215 + 30778216.

It is an arithmetic number, because the mean of its divisors is an integer number (30778216).

Almost surely, 2^61556431 is an apocalyptic number.

61556431 is a deficient number, since it is larger than the sum of its proper divisors (1).

61556431 is an equidigital number, since it uses as much as digits as its factorization.

61556431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 31.

The square root of 61556431 is about 7845.7906548671. The cubic root of 61556431 is about 394.8430311518.

The spelling of 61556431 in words is "sixty-one million, five hundred fifty-six thousand, four hundred thirty-one".