21452375 has 16 divisors (see below), whose sum is σ = 30598464. Its totient is φ = 14709600.

The previous prime is 21452363. The next prime is 21452393. The reversal of 21452375 is 57325412.

It is a happy number.

It is not a de Polignac number, because 21452375 - 2¹⁰ = 21451351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11384 + ... + 13133.

It is an arithmetic number, because the mean of its divisors is an integer number (1912404).

Almost surely, 2^21452375 is an apocalyptic number.

21452375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21452375 is a deficient number, since it is larger than the sum of its proper divisors (9146089).

21452375 is an equidigital number, since it uses as much as digits as its factorization.

21452375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24539 (or 24529 counting only the distinct ones).

The product of its digits is 8400, while the sum is 29.

The square root of 21452375 is about 4631.6708648176. The cubic root of 21452375 is about 277.8594211865.

Adding to 21452375 its reverse (57325412), we get a palindrome (78777787).

The spelling of 21452375 in words is "twenty-one million, four hundred fifty-two thousand, three hundred seventy-five".