20021825 has 6 divisors (see below), whose sum is σ = 24827094. Its totient is φ = 16017440.

The previous prime is 20021821. The next prime is 20021831. The reversal of 20021825 is 52812002.

It can be written as a sum of positive squares in 3 ways, for example, as 246016 + 19775809 = 496^2 + 4447^2 .

It is not a de Polignac number, because 20021825 - 2² = 20021821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20021797 and 20021806.

It is not an unprimeable number, because it can be changed into a prime (20021821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 400412 + ... + 400461.

It is an arithmetic number, because the mean of its divisors is an integer number (4137849).

Almost surely, 2^20021825 is an apocalyptic number.

20021825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20021825 is a deficient number, since it is larger than the sum of its proper divisors (4805269).

20021825 is an equidigital number, since it uses as much as digits as its factorization.

20021825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 800883 (or 800878 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 20021825 is about 4474.5753988507. The cubic root of 20021825 is about 271.5404627065.

Adding to 20021825 its reverse (52812002), we get a palindrome (72833827).

The spelling of 20021825 in words is "twenty million, twenty-one thousand, eight hundred twenty-five".