21102122323 has 4 divisors (see below), whose sum is σ = 22212760360. Its totient is φ = 19991484288.

The previous prime is 21102122311. The next prime is 21102122383. The reversal of 21102122323 is 32322120112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102122323 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 1110638017 = 21102122323 / (2 + 1 + 1 + 0 + 2 + 1 + 2 + 2 + 3 + 2 + 3).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21102122323.

It is not an unprimeable number, because it can be changed into a prime (21102122383) 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, 555318990 + ... + 555319027.

It is an arithmetic number, because the mean of its divisors is an integer number (5553190090).

Almost surely, 2^21102122323 is an apocalyptic number.

21102122323 is a deficient number, since it is larger than the sum of its proper divisors (1110638037).

21102122323 is a wasteful number, since it uses less digits than its factorization.

21102122323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1110638036.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21102122323 its reverse (32322120112), we get a palindrome (53424242435).

The spelling of 21102122323 in words is "twenty-one billion, one hundred two million, one hundred twenty-two thousand, three hundred twenty-three".