21201222020 has 48 divisors (see below), whose sum is σ = 48763705536. Its totient is φ = 7678800000.

The previous prime is 21201222013. The next prime is 21201222041. The reversal of 21201222020 is 2022210212.

It is a junction number, because it is equal to n+sod(n) for n = 21201221986 and 21201222004.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136751 + ... + 247190.

It is an arithmetic number, because the mean of its divisors is an integer number (1015910532).

Almost surely, 2^21201222020 is an apocalyptic number.

21201222020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201222020 is an abundant number, since it is smaller than the sum of its proper divisors (27562483516).

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

21201222020 is a wasteful number, since it uses less digits than its factorization.

21201222020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384212 (or 384210 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21201222020 its reverse (2022210212), we get a palindrome (23223432232).

The spelling of 21201222020 in words is "twenty-one billion, two hundred one million, two hundred twenty-two thousand, twenty".