15625 has 7 divisors (see below), whose sum is σ = 19531.
Its totient is φ = 12500.
The previous prime is 15619. The next prime is 15629. The reversal of 15625 is 52651.
It can be divided in two parts, 156 and 25, that added together give a palindrome (181).
15625 = T124 + T125.
It is a happy number.
The square root of 15625 is 125.
The cubic root of 15625 is 25.
It is a perfect power (a square, a cube, a 6-th power), and thus also a powerful number.
15625 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.
It can be written as a sum of positive squares in 3 ways, for example, as 13689 + 1936 = 117^2 + 44^2
It is an ABA number since it can be written as A⋅BA, here for A=5, B=5.
It is not a de Polignac number, because 15625 - 27 = 15497 is a prime.
It is a Duffinian number.
15625 is a Rhonda number in base 10.
Its product of digits (300) is a multiple of the sum of its prime divisors (5).
It is a nialpdrome in base 5.
It is not an unprimeable number, because it can be changed into a prime (15629) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 6 ways as a sum of consecutive naturals, for example, 3123 + ... + 3127.
15625 is a Friedman number, since it can be written as 5^(5+2)/(6-1), using all its digits and the basic arithmetic operations.
215625 is an apocalyptic number.
15625 is the 125-th square number.
15625 is the 63-rd centered octagonal number.
It is an amenable number.
15625 is a deficient number, since it is larger than the sum of its proper divisors (3906).
15625 is an frugal number, since it uses more digits than its factorization.
15625 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 30 (or 5 counting only the distinct ones).
The product of its digits is 300, while the sum is 19.
The spelling of 15625 in words is "fifteen thousand, six hundred twenty-five".