21252312042 has 32 divisors (see below), whose sum is σ = 45855609408. Its totient is φ = 6527544576.

The previous prime is 21252312019. The next prime is 21252312101. The reversal of 21252312042 is 24021325212.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 198063 + ... + 285890.

It is an arithmetic number, because the mean of its divisors is an integer number (1432987794).

Almost surely, 2^21252312042 is an apocalyptic number.

21252312042 is an abundant number, since it is smaller than the sum of its proper divisors (24603297366).

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

21252312042 is a wasteful number, since it uses less digits than its factorization.

21252312042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484534.

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 21252312042 its reverse (24021325212), we get a palindrome (45273637254).

The spelling of 21252312042 in words is "twenty-one billion, two hundred fifty-two million, three hundred twelve thousand, forty-two".