31640297472 has 336 divisors, whose sum is σ = 105664845312. Its totient is φ = 8935833600.

The previous prime is 31640297471. The next prime is 31640297477. The reversal of 31640297472 is 27479204613.

31640297472 is a `hidden beast` number, since 31 + 64 + 0 + 2 + 97 + 472 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a super-2 number, since 2×31640297472² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31640297471) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 52125393 + ... + 52125999.

Almost surely, 2^31640297472 is an apocalyptic number.

31640297472 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 31640297472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52832422656).

31640297472 is an abundant number, since it is smaller than the sum of its proper divisors (74024547840).

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

31640297472 is a wasteful number, since it uses less digits than its factorization.

31640297472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 747 (or 720 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 45.

The spelling of 31640297472 in words is "thirty-one billion, six hundred forty million, two hundred ninety-seven thousand, four hundred seventy-two".