31218738642 has 192 divisors, whose sum is σ = 85077248256. Its totient is φ = 8054691840.

The previous prime is 31218738601. The next prime is 31218738659. The reversal of 31218738642 is 24683781213.

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, 15663198 + ... + 15665190.

It is an arithmetic number, because the mean of its divisors is an integer number (443110668).

Almost surely, 2^31218738642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31218738642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42538624128).

31218738642 is an abundant number, since it is smaller than the sum of its proper divisors (53858509614).

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

31218738642 is a wasteful number, since it uses less digits than its factorization.

31218738642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2225 (or 2222 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The spelling of 31218738642 in words is "thirty-one billion, two hundred eighteen million, seven hundred thirty-eight thousand, six hundred forty-two".