210021001020 has 72 divisors (see below), whose sum is σ = 638621539920. Its totient is φ = 55868647680.

The previous prime is 210021001013. The next prime is 210021001087. The reversal of 210021001020 is 20100120012.

210021001020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 210021000993 and 210021001011.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1352766 + ... + 1500005.

It is an arithmetic number, because the mean of its divisors is an integer number (8869743610).

Almost surely, 2^210021001020 is an apocalyptic number.

210021001020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

210021001020 is an abundant number, since it is smaller than the sum of its proper divisors (428600538900).

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

210021001020 is a wasteful number, since it uses less digits than its factorization.

210021001020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2853195 (or 2853190 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 210021001020 its reverse (20100120012), we get a palindrome (230121121032).

The spelling of 210021001020 in words is "two hundred ten billion, twenty-one million, one thousand, twenty".