31491271392 has 288 divisors, whose sum is σ = 98355019392. Its totient is φ = 8794469376.

The previous prime is 31491271387. The next prime is 31491271433. The reversal of 31491271392 is 29317219413.

It is a Harshad number since it is a multiple of its sum of digits (42).

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, 51372078 + ... + 51372690.

It is an arithmetic number, because the mean of its divisors is an integer number (341510484).

Almost surely, 2^31491271392 is an apocalyptic number.

31491271392 is a gapful number since it is divisible by the number (32) 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 31491271392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49177509696).

31491271392 is an abundant number, since it is smaller than the sum of its proper divisors (66863748000).

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

31491271392 is a wasteful number, since it uses less digits than its factorization.

31491271392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870 (or 855 counting only the distinct ones).

The product of its digits is 81648, while the sum is 42.

The spelling of 31491271392 in words is "thirty-one billion, four hundred ninety-one million, two hundred seventy-one thousand, three hundred ninety-two".