21210220010020 has 24 divisors (see below), whose sum is σ = 45745285320504. Its totient is φ = 8254788327936.

The previous prime is 21210220009999. The next prime is 21210220010041. The reversal of 21210220010020 is 2001002201212.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21210220009999) and next prime (21210220010041).

It can be written as a sum of positive squares in 4 ways, for example, as 7809744446464 + 13400475563556 = 2794592^2 + 3660666^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14331228997 + ... + 14331230476.

It is an arithmetic number, because the mean of its divisors is an integer number (1906053555021).

Almost surely, 2^{21210220010020} is an apocalyptic number.

21210220010020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210220010020 is an abundant number, since it is smaller than the sum of its proper divisors (24535065310484).

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

21210220010020 is a wasteful number, since it uses less digits than its factorization.

21210220010020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28662459519 (or 28662459517 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21210220010020 its reverse (2001002201212), we get a palindrome (23211222211232).

The spelling of 21210220010020 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, ten thousand, twenty".