21215683338 has 16 divisors (see below), whose sum is σ = 42441493536. Its totient is φ = 7070206640.

The previous prime is 21215683303. The next prime is 21215683403. The reversal of 21215683338 is 83338651212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21215683338.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 394581 + ... + 445112.

It is an arithmetic number, because the mean of its divisors is an integer number (2652593346).

Almost surely, 2^21215683338 is an apocalyptic number.

21215683338 is an abundant number, since it is smaller than the sum of its proper divisors (21225810198).

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

21215683338 is a wasteful number, since it uses less digits than its factorization.

21215683338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843909.

The product of its digits is 207360, while the sum is 42.

The spelling of 21215683338 in words is "twenty-one billion, two hundred fifteen million, six hundred eighty-three thousand, three hundred thirty-eight".