21449725 has 12 divisors (see below), whose sum is σ = 29016000. Its totient is φ = 15599600.

The previous prime is 21449711. The next prime is 21449741. The reversal of 21449725 is 52794412.

It is not a de Polignac number, because 21449725 - 2⁵ = 21449693 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38725 + ... + 39274.

It is an arithmetic number, because the mean of its divisors is an integer number (2418000).

Almost surely, 2^21449725 is an apocalyptic number.

21449725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21449725 is a deficient number, since it is larger than the sum of its proper divisors (7566275).

21449725 is a wasteful number, since it uses less digits than its factorization.

21449725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78020 (or 78015 counting only the distinct ones).

The product of its digits is 20160, while the sum is 34.

The square root of 21449725 is about 4631.3847821143. The cubic root of 21449725 is about 277.8479794419.

The spelling of 21449725 in words is "twenty-one million, four hundred forty-nine thousand, seven hundred twenty-five".