21351915326 has 36 divisors (see below), whose sum is σ = 37412475768. Its totient is φ = 9139339272.

The previous prime is 21351915287. The next prime is 21351915373. The reversal of 21351915326 is 62351915312.

It is a self number, because there is not a number n which added to its sum of digits gives 21351915326.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 26789960 + ... + 26790756.

It is an arithmetic number, because the mean of its divisors is an integer number (1039235438).

Almost surely, 2^21351915326 is an apocalyptic number.

21351915326 is a deficient number, since it is larger than the sum of its proper divisors (16060560442).

21351915326 is an frugal number, since it uses more digits than its factorization.

21351915326 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631 (or 806 counting only the distinct ones).

The product of its digits is 48600, while the sum is 38.

The spelling of 21351915326 in words is "twenty-one billion, three hundred fifty-one million, nine hundred fifteen thousand, three hundred twenty-six".