21105031242 has 192 divisors, whose sum is σ = 50932177920. Its totient is φ = 5782791168.

The previous prime is 21105031237. The next prime is 21105031253. The reversal of 21105031242 is 24213050112.

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, 37486453 + ... + 37487015.

It is an arithmetic number, because the mean of its divisors is an integer number (265271760).

Almost surely, 2^21105031242 is an apocalyptic number.

21105031242 is an abundant number, since it is smaller than the sum of its proper divisors (29827146678).

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

21105031242 is a wasteful number, since it uses less digits than its factorization.

21105031242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685 (or 656 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21105031242 its reverse (24213050112), we get a palindrome (45318081354).

The spelling of 21105031242 in words is "twenty-one billion, one hundred five million, thirty-one thousand, two hundred forty-two".