21253773828 has 48 divisors (see below), whose sum is σ = 56725724160. Its totient is φ = 6067257504.

The previous prime is 21253773811. The next prime is 21253773839. The reversal of 21253773828 is 82837735212.

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, 11088 + ... + 206471.

It is an arithmetic number, because the mean of its divisors is an integer number (1181785920).

Almost surely, 2^21253773828 is an apocalyptic number.

21253773828 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21253773828 is an abundant number, since it is smaller than the sum of its proper divisors (35471950332).

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

21253773828 is a wasteful number, since it uses less digits than its factorization.

21253773828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218736 (or 218734 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 48.

The spelling of 21253773828 in words is "twenty-one billion, two hundred fifty-three million, seven hundred seventy-three thousand, eight hundred twenty-eight".