31386709656 has 128 divisors (see below), whose sum is σ = 87721920000. Its totient is φ = 10398084480.

The previous prime is 31386709649. The next prime is 31386709661. The reversal of 31386709656 is 65690768313.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44268630 + ... + 44269338.

It is an arithmetic number, because the mean of its divisors is an integer number (685327500).

Almost surely, 2^31386709656 is an apocalyptic number.

31386709656 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31386709656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43860960000).

31386709656 is an abundant number, since it is smaller than the sum of its proper divisors (56335210344).

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

31386709656 is a wasteful number, since it uses less digits than its factorization.

31386709656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1694 (or 1684 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 54.

The spelling of 31386709656 in words is "thirty-one billion, three hundred eighty-six million, seven hundred nine thousand, six hundred fifty-six".