21115351572 has 48 divisors (see below), whose sum is σ = 58755766272. Its totient is φ = 5770654560.

The previous prime is 21115351571. The next prime is 21115351583. The reversal of 21115351572 is 27515351112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115351571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5462704 + ... + 5466567.

It is an arithmetic number, because the mean of its divisors is an integer number (1224078464).

Almost surely, 2^21115351572 is an apocalyptic number.

It is an amenable number.

21115351572 is an abundant number, since it is smaller than the sum of its proper divisors (37640414700).

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

21115351572 is a wasteful number, since it uses less digits than its factorization.

21115351572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10929308 (or 10929306 counting only the distinct ones).

The product of its digits is 10500, while the sum is 33.

The spelling of 21115351572 in words is "twenty-one billion, one hundred fifteen million, three hundred fifty-one thousand, five hundred seventy-two".