21123130322221 has 4 divisors (see below), whose sum is σ = 21160649204352. Its totient is φ = 21085611440092.

The previous prime is 21123130322207. The next prime is 21123130322237. The reversal of 21123130322221 is 12222303132112.

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 21123130322221 - 2¹³ = 21123130314029 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 (21123130302221) 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, 18759440221 + ... + 18759441346.

It is an arithmetic number, because the mean of its divisors is an integer number (5290162301088).

Almost surely, 2^{21123130322221} is an apocalyptic number.

It is an amenable number.

21123130322221 is a deficient number, since it is larger than the sum of its proper divisors (37518882131).

21123130322221 is an equidigital number, since it uses as much as digits as its factorization.

21123130322221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37518882130.

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 21123130322221 its reverse (12222303132112), we get a palindrome (33345433454333).

The spelling of 21123130322221 in words is "twenty-one trillion, one hundred twenty-three billion, one hundred thirty million, three hundred twenty-two thousand, two hundred twenty-one".