61131881 has 12 divisors (see below), whose sum is σ = 66706188. Its totient is φ = 55971072.

The previous prime is 61131877. The next prime is 61131883. The reversal of 61131881 is 18813116.

61131881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 17505856 + 43626025 = 4184^2 + 6605^2 .

It is not a de Polignac number, because 61131881 - 2² = 61131877 is a prime.

It is a super-2 number, since 2×61131881² = 7474213749196322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61131883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7835 + ... + 13551.

It is an arithmetic number, because the mean of its divisors is an integer number (5558849).

Almost surely, 2^61131881 is an apocalyptic number.

It is an amenable number.

61131881 is a deficient number, since it is larger than the sum of its proper divisors (5574307).

61131881 is a wasteful number, since it uses less digits than its factorization.

61131881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5788 (or 5771 counting only the distinct ones).

The product of its digits is 1152, while the sum is 29.

The square root of 61131881 is about 7818.6879334067. The cubic root of 61131881 is about 393.9332021917.

Adding to 61131881 its reverse (18813116), we get a palindrome (79944997).

The spelling of 61131881 in words is "sixty-one million, one hundred thirty-one thousand, eight hundred eighty-one".