21202201021 has 4 divisors (see below), whose sum is σ = 22124035872. Its totient is φ = 20280366172.

The previous prime is 21202200959. The next prime is 21202201051. The reversal of 21202201021 is 12010220212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21202201021 - 2¹³ = 21202192829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21202200992 and 21202201010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202201051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 460917391 + ... + 460917436.

It is an arithmetic number, because the mean of its divisors is an integer number (5531008968).

Almost surely, 2^21202201021 is an apocalyptic number.

It is an amenable number.

21202201021 is a deficient number, since it is larger than the sum of its proper divisors (921834851).

21202201021 is an equidigital number, since it uses as much as digits as its factorization.

21202201021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921834850.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21202201021 its reverse (12010220212), we get a palindrome (33212421233).

The spelling of 21202201021 in words is "twenty-one billion, two hundred two million, two hundred one thousand, twenty-one".