61185881 has 2 divisors, whose sum is σ = 61185882. Its totient is φ = 61185880.

The previous prime is 61185863. The next prime is 61185889. The reversal of 61185881 is 18858116.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56010256 + 5175625 = 7484^2 + 2275^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61185881 is a prime.

It is a super-2 number, since 2×61185881² = 7487424067492322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (61185889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30592940 + 30592941.

It is an arithmetic number, because the mean of its divisors is an integer number (30592941).

Almost surely, 2^61185881 is an apocalyptic number.

It is an amenable number.

61185881 is a deficient number, since it is larger than the sum of its proper divisors (1).

61185881 is an equidigital number, since it uses as much as digits as its factorization.

61185881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15360, while the sum is 38.

The square root of 61185881 is about 7822.1404359676. The cubic root of 61185881 is about 394.0491598670.

The spelling of 61185881 in words is "sixty-one million, one hundred eighty-five thousand, eight hundred eighty-one".