21052781372 has 24 divisors (see below), whose sum is σ = 42211644384. Its totient is φ = 8999888832.

The previous prime is 21052781371. The next prime is 21052781389. The reversal of 21052781372 is 27318725012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052781371) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 935843 + ... + 958074.

It is an arithmetic number, because the mean of its divisors is an integer number (1758818516).

Almost surely, 2^21052781372 is an apocalyptic number.

It is an amenable number.

21052781372 is an abundant number, since it is smaller than the sum of its proper divisors (21158863012).

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

21052781372 is a wasteful number, since it uses less digits than its factorization.

21052781372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1894325 (or 1894323 counting only the distinct ones).

The product of its (nonzero) digits is 47040, while the sum is 38.

The spelling of 21052781372 in words is "twenty-one billion, fifty-two million, seven hundred eighty-one thousand, three hundred seventy-two".