21323023451 has 8 divisors (see below), whose sum is σ = 21781617984. Its totient is φ = 20869231240.

The previous prime is 21323023439. The next prime is 21323023453. The reversal of 21323023451 is 15432032312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21323023451 - 2⁶ = 21323023387 is a prime.

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 21323023451.

It is not an unprimeable number, because it can be changed into a prime (21323023453) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1191605 + ... + 1209366.

It is an arithmetic number, because the mean of its divisors is an integer number (2722702248).

Almost surely, 2^21323023451 is an apocalyptic number.

21323023451 is a deficient number, since it is larger than the sum of its proper divisors (458594533).

21323023451 is a wasteful number, since it uses less digits than its factorization.

21323023451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2401161.

The product of its (nonzero) digits is 4320, while the sum is 26.

Adding to 21323023451 its reverse (15432032312), we get a palindrome (36755055763).

The spelling of 21323023451 in words is "twenty-one billion, three hundred twenty-three million, twenty-three thousand, four hundred fifty-one".