21473123 has 12 divisors (see below), whose sum is σ = 25054920. Its totient is φ = 18349632.

The previous prime is 21473107. The next prime is 21473147. The reversal of 21473123 is 32137412.

It is not a de Polignac number, because 21473123 - 2⁴ = 21473107 is a prime.

It is a super-2 number, since 2×21473123² = 922190022746258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21473423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28688 + ... + 29426.

It is an arithmetic number, because the mean of its divisors is an integer number (2087910).

Almost surely, 2^21473123 is an apocalyptic number.

21473123 is a deficient number, since it is larger than the sum of its proper divisors (3581797).

21473123 is an equidigital number, since it uses as much as digits as its factorization.

21473123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1346 (or 1339 counting only the distinct ones).

The product of its digits is 1008, while the sum is 23.

The square root of 21473123 is about 4633.9101199743. The cubic root of 21473123 is about 277.9489710179.

It can be divided in two parts, 214 and 73123, that added together give a palindrome (73337).

The spelling of 21473123 in words is "twenty-one million, four hundred seventy-three thousand, one hundred twenty-three".