21012122220220 has 12 divisors (see below), whose sum is σ = 44125456662504. Its totient is φ = 8404848888080.

The previous prime is 21012122220211. The next prime is 21012122220223. The reversal of 21012122220220 is 2202222121012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012122220223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525303055486 + ... + 525303055525.

It is an arithmetic number, because the mean of its divisors is an integer number (3677121388542).

Almost surely, 2^{21012122220220} is an apocalyptic number.

21012122220220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012122220220 is an abundant number, since it is smaller than the sum of its proper divisors (23113334442284).

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

21012122220220 is a wasteful number, since it uses less digits than its factorization.

21012122220220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050606111020 (or 1050606111018 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21012122220220 its reverse (2202222121012), we get a palindrome (23214344341232).

The spelling of 21012122220220 in words is "twenty-one trillion, twelve billion, one hundred twenty-two million, two hundred twenty thousand, two hundred twenty".