21120212021 has 16 divisors (see below), whose sum is σ = 22472468928. Its totient is φ = 19780320000.

The previous prime is 21120211993. The next prime is 21120212023. The reversal of 21120212021 is 12021202112.

It is a cyclic number.

It is not a de Polignac number, because 21120212021 - 2²² = 21116017717 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120211987 and 21120212005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120212023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7427426 + ... + 7430268.

It is an arithmetic number, because the mean of its divisors is an integer number (1404529308).

Almost surely, 2^21120212021 is an apocalyptic number.

It is an amenable number.

21120212021 is a deficient number, since it is larger than the sum of its proper divisors (1352256907).

21120212021 is a wasteful number, since it uses less digits than its factorization.

21120212021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4852.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21120212021 its reverse (12021202112), we get a palindrome (33141414133).

Subtracting from 21120212021 its reverse (12021202112), we obtain a palindrome (9099009909).

The spelling of 21120212021 in words is "twenty-one billion, one hundred twenty million, two hundred twelve thousand, twenty-one".