21020111112021 has 48 divisors (see below), whose sum is σ = 32852926503936. Its totient is φ = 11919619170144.

The previous prime is 21020111111863. The next prime is 21020111112043. The reversal of 21020111112021 is 12021111102012.

It is a happy number.

It is not a de Polignac number, because 21020111112021 - 2³³ = 21011521177429 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020111117021) 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, 9218340 + ... + 11270226.

It is an arithmetic number, because the mean of its divisors is an integer number (684435968832).

Almost surely, 2^{21020111112021} is an apocalyptic number.

21020111112021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21020111112021 is a deficient number, since it is larger than the sum of its proper divisors (11832815391915).

21020111112021 is a wasteful number, since it uses less digits than its factorization.

21020111112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2052438 (or 2052431 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21020111112021 its reverse (12021111102012), we get a palindrome (33041222214033).

The spelling of 21020111112021 in words is "twenty-one trillion, twenty billion, one hundred eleven million, one hundred twelve thousand, twenty-one".