20890825 has 6 divisors (see below), whose sum is σ = 25904654. Its totient is φ = 16712640.

The previous prime is 20890813. The next prime is 20890867. The reversal of 20890825 is 52809802.

It can be written as a sum of positive squares in 3 ways, for example, as 3225616 + 17665209 = 1796^2 + 4203^2 .

It is not a de Polignac number, because 20890825 - 2⁹ = 20890313 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 5 ways as a sum of consecutive naturals, for example, 417792 + ... + 417841.

Almost surely, 2^20890825 is an apocalyptic number.

20890825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20890825 is a deficient number, since it is larger than the sum of its proper divisors (5013829).

20890825 is an equidigital number, since it uses as much as digits as its factorization.

20890825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 835643 (or 835638 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 20890825 is about 4570.6482034827. The cubic root of 20890825 is about 275.4134826701.

The spelling of 20890825 in words is "twenty million, eight hundred ninety thousand, eight hundred twenty-five".