21013112021 has 8 divisors (see below), whose sum is σ = 24271830144. Its totient is φ = 17979133120.

The previous prime is 21013112017. The next prime is 21013112053. The reversal of 21013112021 is 12021131012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21013112021 - 2² = 21013112017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21013111987 and 21013112005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013112011) 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, 56184605 + ... + 56184978.

It is an arithmetic number, because the mean of its divisors is an integer number (3033978768).

Almost surely, 2^21013112021 is an apocalyptic number.

It is an amenable number.

21013112021 is a deficient number, since it is larger than the sum of its proper divisors (3258718123).

21013112021 is a wasteful number, since it uses less digits than its factorization.

21013112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112369611.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21013112021 its reverse (12021131012), we get a palindrome (33034243033).

The spelling of 21013112021 in words is "twenty-one billion, thirteen million, one hundred twelve thousand, twenty-one".