31811129642 has 4 divisors (see below), whose sum is σ = 47716694466. Its totient is φ = 15905564820.

The previous prime is 31811129599. The next prime is 31811129653. The reversal of 31811129642 is 24692111813.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16578880081 + 15232249561 = 128759^2 + 123419^2 .

It is a junction number, because it is equal to n+sod(n) for n = 31811129596 and 31811129605.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7952782409 + ... + 7952782412.

Almost surely, 2^31811129642 is an apocalyptic number.

31811129642 is a deficient number, since it is larger than the sum of its proper divisors (15905564824).

31811129642 is a wasteful number, since it uses less digits than its factorization.

31811129642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15905564823.

The product of its digits is 20736, while the sum is 38.

The spelling of 31811129642 in words is "thirty-one billion, eight hundred eleven million, one hundred twenty-nine thousand, six hundred forty-two".