20725 has 6 divisors (see below), whose sum is σ = 25730. Its totient is φ = 16560.

The previous prime is 20719. The next prime is 20731. The reversal of 20725 is 52702.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20719) and next prime (20731).

It can be written as a sum of positive squares in 3 ways, for example, as 1681 + 19044 = 41^2 + 138^2 .

It is not a de Polignac number, because 20725 - 2³ = 20717 is a prime.

It is a nialpdrome in base 12.

It is a zygodrome in base 4.

It is a junction number, because it is equal to n+sod(n) for n = 20699 and 20708.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 390 + ... + 439.

2²⁰⁷²⁵ is an apocalyptic number.

20725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20725 is a deficient number, since it is larger than the sum of its proper divisors (5005).

20725 is an equidigital number, since it uses as much as digits as its factorization.

20725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 839 (or 834 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 16.

The square root of 20725 is about 143.9618004889. The cubic root of 20725 is about 27.4682829926.

It can be divided in two parts, 207 and 25, that added together give a palindrome (232).

The spelling of 20725 in words is "twenty thousand, seven hundred twenty-five".