725704645689 has 9 divisors (see below), whose sum is σ = 1048243735279. Its totient is φ = 483801393360.

The previous prime is 725704645643. The next prime is 725704645691. The reversal of 725704645689 is 986546407527.

The square root of 725704645689 is 851883.

It is a perfect power (a square), and thus also a powerful number.

725704645689 is a `hidden beast` number, since 7 + 2 + 5 + 7 + 0 + 4 + 64 + 568 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 174487492089 + 551217153600 = 417717^2 + 742440^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 725704645689 - 2¹¹ = 725704643641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (725704645889) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2413669 + ... + 2697629.

Almost surely, 2^725704645689 is an apocalyptic number.

725704645689 is the 851883-rd square number.

725704645689 is the 425942-nd centered octagonal number.

It is an amenable number.

725704645689 is a deficient number, since it is larger than the sum of its proper divisors (322539089590).

725704645689 is an frugal number, since it uses more digits than its factorization.

725704645689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567928 (or 283964 counting only the distinct ones).

The product of its (nonzero) digits is 101606400, while the sum is 63.

The spelling of 725704645689 in words is "seven hundred twenty-five billion, seven hundred four million, six hundred forty-five thousand, six hundred eighty-nine".