725543621 has 4 divisors (see below), whose sum is σ = 791502144. Its totient is φ = 659585100.

The previous prime is 725543617. The next prime is 725543647. The reversal of 725543621 is 126345527.

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 725543621 - 2² = 725543617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (725543681) 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, 32979245 + ... + 32979266.

It is an arithmetic number, because the mean of its divisors is an integer number (197875536).

Almost surely, 2^725543621 is an apocalyptic number.

It is an amenable number.

725543621 is a deficient number, since it is larger than the sum of its proper divisors (65958523).

725543621 is a wasteful number, since it uses less digits than its factorization.

725543621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65958522.

The product of its digits is 50400, while the sum is 35.

The square root of 725543621 is about 26935.9169326013. The cubic root of 725543621 is about 898.5753679155.

The spelling of 725543621 in words is "seven hundred twenty-five million, five hundred forty-three thousand, six hundred twenty-one".