31987952640 has 792 divisors, whose sum is σ = 133383699072. Its totient is φ = 7060193280.

The previous prime is 31987952629. The next prime is 31987952663. The reversal of 31987952640 is 4625978913.

31987952640 is a `hidden beast` number, since 3 + 1 + 9 + 8 + 79 + 526 + 40 = 666.

It is a super-2 number, since 2×31987952640² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 69995292 + ... + 69995748.

It is a 1-persistent number, because it is pandigital, but 2⋅31987952640 = 63975905280 is not.

Almost surely, 2^31987952640 is an apocalyptic number.

31987952640 is a gapful number since it is divisible by the number (30) 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 31987952640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66691849536).

31987952640 is an abundant number, since it is smaller than the sum of its proper divisors (101395746432).

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

31987952640 is a wasteful number, since it uses less digits than its factorization.

31987952640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 533 (or 505 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The spelling of 31987952640 in words is "thirty-one billion, nine hundred eighty-seven million, nine hundred fifty-two thousand, six hundred forty".