725834137681 has 9 divisors (see below), whose sum is σ = 743144064219. Its totient is φ = 708918491736.

The previous prime is 725834137603. The next prime is 725834137687. The reversal of 725834137681 is 186731438527.

The square root of 725834137681 is 851959.

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

It can be written as a sum of positive squares in only one way, i.e., 1830556225 + 724003581456 = 42785^2 + 850884^2 .

It is not a de Polignac number, because 725834137681 - 2¹¹ = 725834135633 is a prime.

It is a super-2 number, since 2×725834137681² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (725834137687) 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 8 ways as a sum of consecutive naturals, for example, 36624331 + ... + 36644143.

It is an arithmetic number, because the mean of its divisors is an integer number (82571562691).

Almost surely, 2^725834137681 is an apocalyptic number.

725834137681 is the 851959-th square number.

725834137681 is the 425980-th centered octagonal number.

It is an amenable number.

725834137681 is a deficient number, since it is larger than the sum of its proper divisors (17309926538).

725834137681 is an frugal number, since it uses more digits than its factorization.

725834137681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39712 (or 19856 counting only the distinct ones).

The product of its digits is 6773760, while the sum is 55.

The spelling of 725834137681 in words is "seven hundred twenty-five billion, eight hundred thirty-four million, one hundred thirty-seven thousand, six hundred eighty-one".