21102011222021 has 4 divisors (see below), whose sum is σ = 21391079868972. Its totient is φ = 20812942575072.

The previous prime is 21102011222011. The next prime is 21102011222023. The reversal of 21102011222021 is 12022211020112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11374093502500 + 9727917719521 = 3372550^2 + 3118961^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102011222021 - 2¹⁴ = 21102011205637 is a prime.

It is a super-2 number, since 2×21102011222021² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102011222023) 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, 144534323366 + ... + 144534323511.

It is an arithmetic number, because the mean of its divisors is an integer number (5347769967243).

Almost surely, 2^{21102011222021} is an apocalyptic number.

It is an amenable number.

21102011222021 is a deficient number, since it is larger than the sum of its proper divisors (289068646951).

21102011222021 is an equidigital number, since it uses as much as digits as its factorization.

21102011222021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289068646950.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21102011222021 its reverse (12022211020112), we get a palindrome (33124222242133).

The spelling of 21102011222021 in words is "twenty-one trillion, one hundred two billion, eleven million, two hundred twenty-two thousand, twenty-one".