725421 has 4 divisors (see below), whose sum is σ = 967232. Its totient is φ = 483612.

The previous prime is 725399. The next prime is 725423. The reversal of 725421 is 124527.

725421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 725421 - 2⁶ = 725357 is a prime.

It is a D-number.

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 725421.

It is not an unprimeable number, because it can be changed into a prime (725423) 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, 120901 + ... + 120906.

It is an arithmetic number, because the mean of its divisors is an integer number (241808).

2⁷²⁵⁴²¹ is an apocalyptic number.

It is an amenable number.

725421 is a deficient number, since it is larger than the sum of its proper divisors (241811).

725421 is a wasteful number, since it uses less digits than its factorization.

725421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241810.

The product of its digits is 560, while the sum is 21.

The square root of 725421 is about 851.7165021297. The cubic root of 725421 is about 89.8524743614.

Adding to 725421 its reverse (124527), we get a palindrome (849948).

The spelling of 725421 in words is "seven hundred twenty-five thousand, four hundred twenty-one".