21258475 has 24 divisors (see below), whose sum is σ = 30299648. Its totient is φ = 14493600.

The previous prime is 21258443. The next prime is 21258481. The reversal of 21258475 is 57485212.

It is a happy number.

It is not a de Polignac number, because 21258475 - 2⁵ = 21258443 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21258475.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 57742 + ... + 58108.

Almost surely, 2^21258475 is an apocalyptic number.

21258475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21258475 is a deficient number, since it is larger than the sum of its proper divisors (9041173).

21258475 is a wasteful number, since it uses less digits than its factorization.

21258475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 715 (or 710 counting only the distinct ones).

The product of its digits is 22400, while the sum is 34.

The square root of 21258475 is about 4610.6913798258. The cubic root of 21258475 is about 277.0197303779.

The spelling of 21258475 in words is "twenty-one million, two hundred fifty-eight thousand, four hundred seventy-five".