21122223021 has 48 divisors (see below), whose sum is σ = 31187520000. Its totient is φ = 13773283200.

The previous prime is 21122223013. The next prime is 21122223043. The reversal of 21122223021 is 12032222112.

21122223021 is a `hidden beast` number, since 211 + 222 + 230 + 2 + 1 = 666.

It is not a de Polignac number, because 21122223021 - 2³ = 21122223013 is a prime.

It is a super-2 number, since 2×21122223021² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122222985 and 21122223003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122223071) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44096260 + ... + 44096738.

It is an arithmetic number, because the mean of its divisors is an integer number (649740000).

Almost surely, 2^21122223021 is an apocalyptic number.

It is an amenable number.

21122223021 is a deficient number, since it is larger than the sum of its proper divisors (10065296979).

21122223021 is a wasteful number, since it uses less digits than its factorization.

21122223021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1074 (or 1071 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21122223021 its reverse (12032222112), we get a palindrome (33154445133).

Subtracting from 21122223021 its reverse (12032222112), we obtain a palindrome (9090000909).

The spelling of 21122223021 in words is "twenty-one billion, one hundred twenty-two million, two hundred twenty-three thousand, twenty-one".