21743725 has 12 divisors (see below), whose sum is σ = 27030016. Its totient is φ = 17351280.

The previous prime is 21743699. The next prime is 21743737. The reversal of 21743725 is 52734712.

It is not a de Polignac number, because 21743725 - 2⁵ = 21743693 is a prime.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 12244 + ... + 13906.

Almost surely, 2^21743725 is an apocalyptic number.

21743725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21743725 is a deficient number, since it is larger than the sum of its proper divisors (5286291).

21743725 is a wasteful number, since it uses less digits than its factorization.

21743725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2196 (or 2191 counting only the distinct ones).

The product of its digits is 11760, while the sum is 31.

The square root of 21743725 is about 4663.0167273987. The cubic root of 21743725 is about 279.1116616463. Note that the first 3 decimals are identical.

The spelling of 21743725 in words is "twenty-one million, seven hundred forty-three thousand, seven hundred twenty-five".