61881985431 has 12 divisors (see below), whose sum is σ = 102154388752. Its totient is φ = 35361134496.

The previous prime is 61881985427. The next prime is 61881985453. The reversal of 61881985431 is 13458918816.

It is a happy number.

61881985431 is a `hidden beast` number, since 6 + 1 + 8 + 8 + 1 + 98 + 543 + 1 = 666.

61881985431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61881985431 - 2² = 61881985427 is a prime.

It is a super-2 number, since 2×61881985431² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61881985411) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 491126806 + ... + 491126931.

Almost surely, 2^61881985431 is an apocalyptic number.

61881985431 is a deficient number, since it is larger than the sum of its proper divisors (40272403321).

61881985431 is a wasteful number, since it uses less digits than its factorization.

61881985431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 982253750 (or 982253747 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 54.

The spelling of 61881985431 in words is "sixty-one billion, eight hundred eighty-one million, nine hundred eighty-five thousand, four hundred thirty-one".