31663981440 has 768 divisors, whose sum is σ = 135701354880. Its totient is φ = 6624903168.

The previous prime is 31663981381. The next prime is 31663981463. The reversal of 31663981440 is 4418936613.

31663981440 is a `hidden beast` number, since 3 + 1 + 6 + 639 + 8 + 1 + 4 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 101162724 + ... + 101163036.

Almost surely, 2^31663981440 is an apocalyptic number.

31663981440 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 31663981440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67850677440).

31663981440 is an abundant number, since it is smaller than the sum of its proper divisors (104037373440).

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

31663981440 is a wasteful number, since it uses less digits than its factorization.

31663981440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551 (or 536 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 31663981440 in words is "thirty-one billion, six hundred sixty-three million, nine hundred eighty-one thousand, four hundred forty".