22121221020 has 24 divisors (see below), whose sum is σ = 61939419024. Its totient is φ = 5898992256.

The previous prime is 22121221013. The next prime is 22121221021. The reversal of 22121221020 is 2012212122.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22121221021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 184343449 + ... + 184343568.

It is an arithmetic number, because the mean of its divisors is an integer number (2580809126).

Almost surely, 2^22121221020 is an apocalyptic number.

22121221020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22121221020 is an abundant number, since it is smaller than the sum of its proper divisors (39818198004).

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

22121221020 is a wasteful number, since it uses less digits than its factorization.

22121221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368687029 (or 368687027 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 22121221020 its reverse (2012212122), we get a palindrome (24133433142).

The spelling of 22121221020 in words is "twenty-two billion, one hundred twenty-one million, two hundred twenty-one thousand, twenty".