31871921730 has 96 divisors (see below), whose sum is σ = 85763966400. Its totient is φ = 7517594880.

The previous prime is 31871921701. The next prime is 31871921743. The reversal of 31871921730 is 3712917813.

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, 416496 + ... + 487044.

It is an arithmetic number, because the mean of its divisors is an integer number (893374650).

Almost surely, 2^31871921730 is an apocalyptic number.

31871921730 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31871921730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42881983200).

31871921730 is an abundant number, since it is smaller than the sum of its proper divisors (53892044670).

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

31871921730 is a wasteful number, since it uses less digits than its factorization.

31871921730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70644 (or 70607 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 42.

The spelling of 31871921730 in words is "thirty-one billion, eight hundred seventy-one million, nine hundred twenty-one thousand, seven hundred thirty".