8257973521561 has 9 divisors (see below), whose sum is σ = 8533044919893. Its totient is φ = 7991501068860.

The previous prime is 8257973521547. The next prime is 8257973521619. The reversal of 8257973521561 is 1651253797528.

The square root of 8257973521561 is 2873669.

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

It is not a de Polignac number, because 8257973521561 - 2²³ = 8257965132953 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 8257973521561.

It is not an unprimeable number, because it can be changed into a prime (8257973521541) 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, 89037390 + ... + 89130088.

Almost surely, 2^{8257973521561} is an apocalyptic number.

8257973521561 is the 2873669-th square number.

8257973521561 is the 1436835-th centered octagonal number.

It is an amenable number.

8257973521561 is a deficient number, since it is larger than the sum of its proper divisors (275071398332).

8257973521561 is an frugal number, since it uses more digits than its factorization.

8257973521561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185460 (or 92730 counting only the distinct ones).

The product of its digits is 31752000, while the sum is 61.

The spelling of 8257973521561 in words is "eight trillion, two hundred fifty-seven billion, nine hundred seventy-three million, five hundred twenty-one thousand, five hundred sixty-one".