21221002210020 has 48 divisors (see below), whose sum is σ = 60031371216768. Its totient is φ = 5600594396160.

The previous prime is 21221002209971. The next prime is 21221002210049. The reversal of 21221002210020 is 2001220012212.

It is a Harshad number since it is a multiple of its sum of digits (15).

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, 1823104336 + ... + 1823115975.

It is an arithmetic number, because the mean of its divisors is an integer number (1250653567016).

Almost surely, 2^{21221002210020} is an apocalyptic number.

21221002210020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221002210020 is an abundant number, since it is smaller than the sum of its proper divisors (38810369006748).

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

21221002210020 is a wasteful number, since it uses less digits than its factorization.

21221002210020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3646220420 (or 3646220418 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21221002210020 its reverse (2001220012212), we get a palindrome (23222222222232).

The spelling of 21221002210020 in words is "twenty-one trillion, two hundred twenty-one billion, two million, two hundred ten thousand, twenty".