21310023 has 8 divisors (see below), whose sum is σ = 32472448. Its totient is φ = 12177144.

The previous prime is 21310021. The next prime is 21310043. The reversal of 21310023 is 32001312.

It is a happy number.

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

It is not a de Polignac number, because 21310023 - 2¹ = 21310021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21309990 and 21310008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 507361 + ... + 507402.

It is an arithmetic number, because the mean of its divisors is an integer number (4059056).

Almost surely, 2^21310023 is an apocalyptic number.

21310023 is a deficient number, since it is larger than the sum of its proper divisors (11162425).

21310023 is a wasteful number, since it uses less digits than its factorization.

21310023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1014773.

The product of its (nonzero) digits is 36, while the sum is 12.

The square root of 21310023 is about 4616.2780462186. The cubic root of 21310023 is about 277.2434574105.

Adding to 21310023 its reverse (32001312), we get a palindrome (53311335).

The spelling of 21310023 in words is "twenty-one million, three hundred ten thousand, twenty-three".