21790825 has 24 divisors (see below), whose sum is σ = 31069440. Its totient is φ = 14851200.

The previous prime is 21790801. The next prime is 21790841. The reversal of 21790825 is 52809712.

It is not a de Polignac number, because 21790825 - 2⁷ = 21790697 is a prime.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

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, 41565 + ... + 42085.

It is an arithmetic number, because the mean of its divisors is an integer number (1294560).

Almost surely, 2^21790825 is an apocalyptic number.

21790825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21790825 is a deficient number, since it is larger than the sum of its proper divisors (9278615).

21790825 is a wasteful number, since it uses less digits than its factorization.

21790825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777 (or 772 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 21790825 is about 4668.0643740206. The cubic root of 21790825 is about 279.3130481539.

The spelling of 21790825 in words is "twenty-one million, seven hundred ninety thousand, eight hundred twenty-five".