21975425 has 12 divisors (see below), whose sum is σ = 27307776. Its totient is φ = 17542800.

The previous prime is 21975413. The next prime is 21975427. The reversal of 21975425 is 52457912.

It is not a de Polignac number, because 21975425 - 2⁶ = 21975361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21975427) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 21680 + ... + 22670.

It is an arithmetic number, because the mean of its divisors is an integer number (2275648).

Almost surely, 2^21975425 is an apocalyptic number.

21975425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21975425 is a deficient number, since it is larger than the sum of its proper divisors (5332351).

21975425 is an equidigital number, since it uses as much as digits as its factorization.

21975425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888 (or 1883 counting only the distinct ones).

The product of its digits is 25200, while the sum is 35.

The square root of 21975425 is about 4687.7953240303. The cubic root of 21975425 is about 280.0995606831.

The spelling of 21975425 in words is "twenty-one million, nine hundred seventy-five thousand, four hundred twenty-five".