21020202221220 has 72 divisors (see below), whose sum is σ = 63897814116864. Its totient is φ = 5593384266048.

The previous prime is 21020202221219. The next prime is 21020202221233. The reversal of 21020202221220 is 2212220202012.

21020202221220 is a `hidden beast` number, since 2 + 1 + 0 + 20 + 202 + 221 + 220 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21020202221193 and 21020202221202.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 124946884 + ... + 125115003.

It is an arithmetic number, because the mean of its divisors is an integer number (887469640512).

Almost surely, 2^{21020202221220} is an apocalyptic number.

21020202221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020202221220 is an abundant number, since it is smaller than the sum of its proper divisors (42877611895644).

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

21020202221220 is a wasteful number, since it uses less digits than its factorization.

21020202221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250062369 (or 250062364 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21020202221220 its reverse (2212220202012), we get a palindrome (23232422423232).

The spelling of 21020202221220 in words is "twenty-one trillion, twenty billion, two hundred two million, two hundred twenty-one thousand, two hundred twenty".