21674825 has 18 divisors (see below), whose sum is σ = 27441882. Its totient is φ = 16982400.

The previous prime is 21674819. The next prime is 21674833. The reversal of 21674825 is 52847612.

It can be written as a sum of positive squares in 9 ways, for example, as 20097289 + 1577536 = 4483^2 + 1256^2 .

It is not a de Polignac number, because 21674825 - 2⁶ = 21674761 is a prime.

It is a Duffinian 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 17 ways as a sum of consecutive naturals, for example, 92909 + ... + 93141.

It is an arithmetic number, because the mean of its divisors is an integer number (1524549).

Almost surely, 2^21674825 is an apocalyptic number.

21674825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21674825 is a deficient number, since it is larger than the sum of its proper divisors (5767057).

21674825 is an equidigital number, since it uses as much as digits as its factorization.

21674825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365 (or 299 counting only the distinct ones).

The product of its digits is 26880, while the sum is 35.

The square root of 21674825 is about 4655.6229443545. The cubic root of 21674825 is about 278.8165398472.

The spelling of 21674825 in words is "twenty-one million, six hundred seventy-four thousand, eight hundred twenty-five".