21234315023 has 4 divisors (see below), whose sum is σ = 21292174560. Its totient is φ = 21176455488.

The previous prime is 21234315019. The next prime is 21234315049. The reversal of 21234315023 is 32051343212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21234315023 - 2² = 21234315019 is a prime.

It is a super-2 number, since 2×21234315023² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21234314983 and 21234315001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234315073) 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, 28929218 + ... + 28929951.

It is an arithmetic number, because the mean of its divisors is an integer number (5323043640).

Almost surely, 2^21234315023 is an apocalyptic number.

21234315023 is a deficient number, since it is larger than the sum of its proper divisors (57859537).

21234315023 is an equidigital number, since it uses as much as digits as its factorization.

21234315023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57859536.

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

Adding to 21234315023 its reverse (32051343212), we get a palindrome (53285658235).

The spelling of 21234315023 in words is "twenty-one billion, two hundred thirty-four million, three hundred fifteen thousand, twenty-three".