21022220020 has 12 divisors (see below), whose sum is σ = 44146662084. Its totient is φ = 8408888000.

The previous prime is 21022220017. The next prime is 21022220047. The reversal of 21022220020 is 2002222012.

It can be written as a sum of positive squares in 2 ways, for example, as 13845758224 + 7176461796 = 117668^2 + 84714^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525555481 + ... + 525555520.

It is an arithmetic number, because the mean of its divisors is an integer number (3678888507).

Almost surely, 2^21022220020 is an apocalyptic number.

21022220020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21022220020 is an abundant number, since it is smaller than the sum of its proper divisors (23124442064).

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

21022220020 is a wasteful number, since it uses less digits than its factorization.

21022220020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1051111010 (or 1051111008 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

Adding to 21022220020 its reverse (2002222012), we get a palindrome (23024442032).

The spelling of 21022220020 in words is "twenty-one billion, twenty-two million, two hundred twenty thousand, twenty".