725716639 has 2 divisors, whose sum is σ = 725716640. Its totient is φ = 725716638.

The previous prime is 725716543. The next prime is 725716681. The reversal of 725716639 is 936617527.

It is a strong prime.

It is an emirp because it is prime and its reverse (936617527) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 725716639 - 2⁹ = 725716127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (725716139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 362858319 + 362858320.

It is an arithmetic number, because the mean of its divisors is an integer number (362858320).

Almost surely, 2^725716639 is an apocalyptic number.

725716639 is a deficient number, since it is larger than the sum of its proper divisors (1).

725716639 is an equidigital number, since it uses as much as digits as its factorization.

725716639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 476280, while the sum is 46.

The square root of 725716639 is about 26939.1284008967. The cubic root of 725716639 is about 898.6467890091.

The spelling of 725716639 in words is "seven hundred twenty-five million, seven hundred sixteen thousand, six hundred thirty-nine".