20425 has 12 divisors (see below), whose sum is σ = 27280. Its totient is φ = 15120.

The previous prime is 20411. The next prime is 20431. The reversal of 20425 is 52402.

It is a happy number.

20425 is an esthetic number in base 6, because in such base its adjacent digits differ by 1.

It is not a de Polignac number, because 20425 - 2⁵ = 20393 is a prime.

20425 is a lucky number.

It is a plaindrome in base 7.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 454 + ... + 496.

2²⁰⁴²⁵ is an apocalyptic number.

20425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20425 is a deficient number, since it is larger than the sum of its proper divisors (6855).

20425 is a wasteful number, since it uses less digits than its factorization.

20425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 13.

The square root of 20425 is about 142.9160592796. The cubic root of 20425 is about 27.3351013464.

Adding to 20425 its reverse (52402), we get a palindrome (72827).

The spelling of 20425 in words is "twenty thousand, four hundred twenty-five".