21412725 has 24 divisors (see below), whose sum is σ = 35896512. Its totient is φ = 11260800.

The previous prime is 21412717. The next prime is 21412739. The reversal of 21412725 is 52721412.

It is not a de Polignac number, because 21412725 - 2³ = 21412717 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21412695 and 21412704.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3520 + ... + 7430.

It is an arithmetic number, because the mean of its divisors is an integer number (1495688).

Almost surely, 2^21412725 is an apocalyptic number.

21412725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21412725 is a deficient number, since it is larger than the sum of its proper divisors (14483787).

21412725 is a wasteful number, since it uses less digits than its factorization.

21412725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3997 (or 3992 counting only the distinct ones).

The product of its digits is 1120, while the sum is 24.

The square root of 21412725 is about 4627.3885724024. The cubic root of 21412725 is about 277.6881282550.

The spelling of 21412725 in words is "twenty-one million, four hundred twelve thousand, seven hundred twenty-five".