725999991 has 8 divisors (see below), whose sum is σ = 1010087040. Its totient is φ = 462956472.

The previous prime is 725999969. The next prime is 725999999. The reversal of 725999991 is 199999527.

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

It is not a de Polignac number, because 725999991 - 2¹⁰ = 725998967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (725999999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5260801 + ... + 5260938.

It is an arithmetic number, because the mean of its divisors is an integer number (126260880).

Almost surely, 2^725999991 is an apocalyptic number.

725999991 is a deficient number, since it is larger than the sum of its proper divisors (284087049).

725999991 is a wasteful number, since it uses less digits than its factorization.

725999991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10521765.

The product of its digits is 4133430, while the sum is 60.

The square root of 725999991 is about 26944.3870036043. The cubic root of 725999991 is about 898.7637309937.

The spelling of 725999991 in words is "seven hundred twenty-five million, nine hundred ninety-nine thousand, nine hundred ninety-one".