21021110120021 has 32 divisors (see below), whose sum is σ = 24998173820928. Its totient is φ = 17459919671040.

The previous prime is 21021110120011. The next prime is 21021110120047. The reversal of 21021110120021 is 12002101112012.

It is not a de Polignac number, because 21021110120021 - 2²² = 21021105925717 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21021110119978 and 21021110120005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021110120011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6708461 + ... + 9329826.

It is an arithmetic number, because the mean of its divisors is an integer number (781192931904).

Almost surely, 2^{21021110120021} is an apocalyptic number.

It is an amenable number.

21021110120021 is a deficient number, since it is larger than the sum of its proper divisors (3977063700907).

21021110120021 is a wasteful number, since it uses less digits than its factorization.

21021110120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16038521.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21021110120021 its reverse (12002101112012), we get a palindrome (33023211232033).

The spelling of 21021110120021 in words is "twenty-one trillion, twenty-one billion, one hundred ten million, one hundred twenty thousand, twenty-one".