21459123 has 24 divisors (see below), whose sum is σ = 35779328. Its totient is φ = 12139632.

The previous prime is 21459079. The next prime is 21459131. The reversal of 21459123 is 32195412.

It is not a de Polignac number, because 21459123 - 2⁹ = 21458611 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21459133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4836 + ... + 8142.

Almost surely, 2^21459123 is an apocalyptic number.

21459123 is a deficient number, since it is larger than the sum of its proper divisors (14320205).

21459123 is a wasteful number, since it uses less digits than its factorization.

21459123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3423 (or 3420 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 21459123 is about 4632.3992703566. The cubic root of 21459123 is about 277.8885523637. Note that the first 3 decimals are identical.

The spelling of 21459123 in words is "twenty-one million, four hundred fifty-nine thousand, one hundred twenty-three".