725636 has 6 divisors (see below), whose sum is σ = 1269870. Its totient is φ = 362816.

The previous prime is 725603. The next prime is 725639. The reversal of 725636 is 636527.

It can be written as a sum of positive squares in only one way, i.e., 722500 + 3136 = 850^2 + 56^2 .

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 725599 and 725608.

It is not an unprimeable number, because it can be changed into a prime (725639) by changing a digit.

725636 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 90701 + ... + 90708.

It is an arithmetic number, because the mean of its divisors is an integer number (211645).

2⁷²⁵⁶³⁶ is an apocalyptic number.

It is an amenable number.

725636 is a deficient number, since it is larger than the sum of its proper divisors (544234).

725636 is a wasteful number, since it uses less digits than its factorization.

725636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181413 (or 181411 counting only the distinct ones).

The product of its digits is 7560, while the sum is 29.

The square root of 725636 is about 851.8427084856. The cubic root of 725636 is about 89.8613502986.

The spelling of 725636 in words is "seven hundred twenty-five thousand, six hundred thirty-six".