8157521761 has 9 divisors (see below), whose sum is σ = 8219311443. Its totient is φ = 8096195160.

The previous prime is 8157521681. The next prime is 8157521789. The reversal of 8157521761 is 1671257518.

The square root of 8157521761 is 90319.

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., 89889361 + 8067632400 = 9481^2 + 89820^2 .

It is not a de Polignac number, because 8157521761 - 2⁹ = 8157521249 is a prime.

It is a super-2 number, since 2×8157521761² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8157524761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 16347490 + ... + 16347988.

It is an arithmetic number, because the mean of its divisors is an integer number (913256827).

Almost surely, 2^8157521761 is an apocalyptic number.

8157521761 is the 90319-th square number.

8157521761 is the 45160-th centered octagonal number.

It is an amenable number.

8157521761 is a deficient number, since it is larger than the sum of its proper divisors (61789682).

8157521761 is an frugal number, since it uses more digits than its factorization.

8157521761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360 (or 680 counting only the distinct ones).

The product of its digits is 117600, while the sum is 43.

The cubic root of 8157521761 is about 2013.0415870739.

The spelling of 8157521761 in words is "eight billion, one hundred fifty-seven million, five hundred twenty-one thousand, seven hundred sixty-one".