87521897281 has 27 divisors (see below), whose sum is σ = 110279171043. Its totient is φ = 69226794000.

The previous prime is 87521897251. The next prime is 87521897291. The reversal of 87521897281 is 18279812578.

The square root of 87521897281 is 295841.

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., 12947026225 + 74574871056 = 113785^2 + 273084^2 .

It is not a de Polignac number, because 87521897281 - 2²⁷ = 87387679553 is a prime.

It is a super-2 number, since 2×87521897281² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87521897201) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 26919906 + ... + 26923156.

Almost surely, 2^87521897281 is an apocalyptic number.

87521897281 is the 295841-st square number.

87521897281 is the 147921-st centered octagonal number.

It is an amenable number.

87521897281 is a deficient number, since it is larger than the sum of its proper divisors (22757273762).

87521897281 is an frugal number, since it uses more digits than its factorization.

87521897281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6542 (or 3271 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 58.

The spelling of 87521897281 in words is "eighty-seven billion, five hundred twenty-one million, eight hundred ninety-seven thousand, two hundred eighty-one".