725681 has 8 divisors (see below), whose sum is σ = 813504. Its totient is φ = 641520.

The previous prime is 725671. The next prime is 725687. The reversal of 725681 is 186527.

725681 = T₁₉₃ + T₁₉₄ + ... + T₂₂₅.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 725681 - 2¹⁸ = 463537 is a prime.

It is a super-2 number, since 2×725681² = 1053225827522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 725681.

It is not an unprimeable number, because it can be changed into a prime (725687) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 485 + ... + 1298.

It is an arithmetic number, because the mean of its divisors is an integer number (101688).

2⁷²⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

725681 is a deficient number, since it is larger than the sum of its proper divisors (87823).

725681 is a wasteful number, since it uses less digits than its factorization.

725681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1831.

The product of its digits is 3360, while the sum is 29.

The square root of 725681 is about 851.8691214030. The cubic root of 725681 is about 89.8632078310.

It can be divided in two parts, 7256 and 81, that added together give a palindrome (7337).

The spelling of 725681 in words is "seven hundred twenty-five thousand, six hundred eighty-one".