21123302233021 has 4 divisors (see below), whose sum is σ = 21123321164892. Its totient is φ = 21123283301152.

The previous prime is 21123302233001. The next prime is 21123302233057. The reversal of 21123302233021 is 12033220332112.

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 9462477340996 + 11660824892025 = 3076114^2 + 3414795^2 .

It is a cyclic number.

It is not a de Polignac number, because 21123302233021 - 2²⁷ = 21123168015293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123302233001) 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, 7679986 + ... + 10061251.

It is an arithmetic number, because the mean of its divisors is an integer number (5280830291223).

Almost surely, 2^{21123302233021} is an apocalyptic number.

It is an amenable number.

21123302233021 is a deficient number, since it is larger than the sum of its proper divisors (18931871).

21123302233021 is a wasteful number, since it uses less digits than its factorization.

21123302233021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18931870.

The product of its (nonzero) digits is 2592, while the sum is 25.

Adding to 21123302233021 its reverse (12033220332112), we get a palindrome (33156522565133).

The spelling of 21123302233021 in words is "twenty-one trillion, one hundred twenty-three billion, three hundred two million, two hundred thirty-three thousand, twenty-one".