21021020000 has 60 divisors (see below), whose sum is σ = 51714911556. Its totient is φ = 8408400000.

The previous prime is 21021019997. The next prime is 21021020057. The reversal of 21021020000 is 2012012.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21021020000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 505526 + ... + 545525.

Almost surely, 2^21021020000 is an apocalyptic number.

21021020000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021020000 is an abundant number, since it is smaller than the sum of its proper divisors (30693891556).

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

21021020000 is an equidigital number, since it uses as much as digits as its factorization.

21021020000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1051081 (or 1051058 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 21021020000 its reverse (2012012), we get a palindrome (21023032012).

The spelling of 21021020000 in words is "twenty-one billion, twenty-one million, twenty thousand".