21221020020220 has 48 divisors (see below), whose sum is σ = 45516530683008. Its totient is φ = 8307034104320.

The previous prime is 21221020020157. The next prime is 21221020020259. The reversal of 21221020020220 is 2202002012212.

It is a junction number, because it is equal to n+sod(n) for n = 21221020020194 and 21221020020203.

It is a congruent number.

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, 9161760 + ... + 11241880.

It is an arithmetic number, because the mean of its divisors is an integer number (948261055896).

Almost surely, 2^{21221020020220} is an apocalyptic number.

21221020020220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221020020220 is an abundant number, since it is smaller than the sum of its proper divisors (24295510662788).

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

21221020020220 is a wasteful number, since it uses less digits than its factorization.

21221020020220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2091030 (or 2091028 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21221020020220 its reverse (2202002012212), we get a palindrome (23423022032432).

The spelling of 21221020020220 in words is "twenty-one trillion, two hundred twenty-one billion, twenty million, twenty thousand, two hundred twenty".