725165661 has 8 divisors (see below), whose sum is σ = 1054786464. Its totient is φ = 439494320.

The previous prime is 725165659. The next prime is 725165687. The reversal of 725165661 is 166561527.

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

It is a cyclic number.

It is not a de Polignac number, because 725165661 - 2¹ = 725165659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (725165611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10987326 + ... + 10987391.

It is an arithmetic number, because the mean of its divisors is an integer number (131848308).

Almost surely, 2^725165661 is an apocalyptic number.

It is an amenable number.

725165661 is a deficient number, since it is larger than the sum of its proper divisors (329620803).

725165661 is a wasteful number, since it uses less digits than its factorization.

725165661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21974731.

The product of its digits is 75600, while the sum is 39.

The square root of 725165661 is about 26928.9001075053. The cubic root of 725165661 is about 898.4193081338.

The spelling of 725165661 in words is "seven hundred twenty-five million, one hundred sixty-five thousand, six hundred sixty-one".