31661239734 has 96 divisors (see below), whose sum is σ = 73753804800. Its totient is φ = 9796852800.

The previous prime is 31661239711. The next prime is 31661239783. The reversal of 31661239734 is 43793216613.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31661239734.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1455067 + ... + 1476665.

It is an arithmetic number, because the mean of its divisors is an integer number (768268800).

Almost surely, 2^31661239734 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31661239734, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36876902400).

31661239734 is an abundant number, since it is smaller than the sum of its proper divisors (42092565066).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31661239734 is a wasteful number, since it uses less digits than its factorization.

31661239734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21746 (or 21743 counting only the distinct ones).

The product of its digits is 489888, while the sum is 45.

The spelling of 31661239734 in words is "thirty-one billion, six hundred sixty-one million, two hundred thirty-nine thousand, seven hundred thirty-four".