21452431 has 32 divisors (see below), whose sum is σ = 29836800. Its totient is φ = 14878080.

The previous prime is 21452413. The next prime is 21452443. The reversal of 21452431 is 13425412.

It is not a de Polignac number, because 21452431 - 2⁹ = 21451919 is a prime.

It is a super-2 number, since 2×21452431² = 920413591619522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21452411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28660 + ... + 29398.

It is an arithmetic number, because the mean of its divisors is an integer number (932400).

Almost surely, 2^21452431 is an apocalyptic number.

21452431 is a deficient number, since it is larger than the sum of its proper divisors (8384369).

21452431 is a wasteful number, since it uses less digits than its factorization.

21452431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799.

The product of its digits is 960, while the sum is 22.

The square root of 21452431 is about 4631.6769101482. The cubic root of 21452431 is about 277.8596629642.

Adding to 21452431 its reverse (13425412), we get a palindrome (34877843).

The spelling of 21452431 in words is "twenty-one million, four hundred fifty-two thousand, four hundred thirty-one".