21023644000 has 48 divisors (see below), whose sum is σ = 51655103136. Its totient is φ = 8409456000.

The previous prime is 21023643983. The next prime is 21023644007. The reversal of 21023644000 is 44632012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023644007) 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, 2623956 + ... + 2631955.

It is an arithmetic number, because the mean of its divisors is an integer number (1076147982).

Almost surely, 2^21023644000 is an apocalyptic number.

21023644000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21023644000 is an abundant number, since it is smaller than the sum of its proper divisors (30631459136).

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

21023644000 is an equidigital number, since it uses as much as digits as its factorization.

21023644000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5255936 (or 5255918 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The spelling of 21023644000 in words is "twenty-one billion, twenty-three million, six hundred forty-four thousand".