21201102021 has 8 divisors (see below), whose sum is σ = 30837966624. Its totient is φ = 12849152720.

The previous prime is 21201102017. The next prime is 21201102023. The reversal of 21201102021 is 12020110212.

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 21201102021 - 2² = 21201102017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201101988 and 21201102006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201102023) 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, 321228786 + ... + 321228851.

It is an arithmetic number, because the mean of its divisors is an integer number (3854745828).

Almost surely, 2^21201102021 is an apocalyptic number.

It is an amenable number.

21201102021 is a deficient number, since it is larger than the sum of its proper divisors (9636864603).

21201102021 is a wasteful number, since it uses less digits than its factorization.

21201102021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 642457651.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21201102021 its reverse (12020110212), we get a palindrome (33221212233).

The spelling of 21201102021 in words is "twenty-one billion, two hundred one million, one hundred two thousand, twenty-one".