31215212442 has 96 divisors (see below), whose sum is σ = 72145494720. Its totient is φ = 9726393600.

The previous prime is 31215212419. The next prime is 31215212489. The reversal of 31215212442 is 24421251213.

31215212442 is a `hidden beast` number, since 3 + 1 + 2 + 1 + 5 + 212 + 442 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8103817 + ... + 8107667.

It is an arithmetic number, because the mean of its divisors is an integer number (751515570).

Almost surely, 2^31215212442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31215212442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36072747360).

31215212442 is an abundant number, since it is smaller than the sum of its proper divisors (40930282278).

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

31215212442 is a wasteful number, since it uses less digits than its factorization.

31215212442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4188 (or 4185 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

Adding to 31215212442 its reverse (24421251213), we get a palindrome (55636463655).

The spelling of 31215212442 in words is "thirty-one billion, two hundred fifteen million, two hundred twelve thousand, four hundred forty-two".