725649 has 4 divisors (see below), whose sum is σ = 967536. Its totient is φ = 483764.

The previous prime is 725639. The next prime is 725653. The reversal of 725649 is 946527.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 725649 - 2⁸ = 725393 is a prime.

It is a D-number.

725649 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 725649.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120939 + ... + 120944.

It is an arithmetic number, because the mean of its divisors is an integer number (241884).

2⁷²⁵⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

725649 is a deficient number, since it is larger than the sum of its proper divisors (241887).

725649 is a wasteful number, since it uses less digits than its factorization.

725649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241886.

The product of its digits is 15120, while the sum is 33.

The square root of 725649 is about 851.8503389681. The cubic root of 725649 is about 89.8618869269.

The spelling of 725649 in words is "seven hundred twenty-five thousand, six hundred forty-nine".