21221001201021 has 4 divisors (see below), whose sum is σ = 28294668268032. Its totient is φ = 14147334134012.

The previous prime is 21221001201019. The next prime is 21221001201053. The reversal of 21221001201021 is 12010210012212.

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 21221001201021 - 2¹ = 21221001201019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221001205021) 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, 3536833533501 + ... + 3536833533506.

It is an arithmetic number, because the mean of its divisors is an integer number (7073667067008).

Almost surely, 2^{21221001201021} is an apocalyptic number.

It is an amenable number.

21221001201021 is a deficient number, since it is larger than the sum of its proper divisors (7073667067011).

21221001201021 is an equidigital number, since it uses as much as digits as its factorization.

21221001201021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7073667067010.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21221001201021 its reverse (12010210012212), we get a palindrome (33231211213233).

The spelling of 21221001201021 in words is "twenty-one trillion, two hundred twenty-one billion, one million, two hundred one thousand, twenty-one".