987731859409 has 9 divisors (see below), whose sum is σ = 997517972763. Its totient is φ = 978040857312.

The previous prime is 987731859407. The next prime is 987731859449. The reversal of 987731859409 is 904958137789.

The square root of 987731859409 is 993847.

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., 105334649809 + 882397209600 = 324553^2 + 939360^2 .

It is not a de Polignac number, because 987731859409 - 2¹ = 987731859407 is a prime.

It is a super-2 number, since 2×987731859409² (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 (987731859407) 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, 102361417 + ... + 102371065.

It is an arithmetic number, because the mean of its divisors is an integer number (110835330307).

Almost surely, 2^987731859409 is an apocalyptic number.

987731859409 is the 993847-th square number.

987731859409 is the 496924-th centered octagonal number.

It is an amenable number.

987731859409 is a deficient number, since it is larger than the sum of its proper divisors (9786113354).

987731859409 is an frugal number, since it uses more digits than its factorization.

987731859409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19504 (or 9752 counting only the distinct ones).

The product of its (nonzero) digits is 137168640, while the sum is 70.

The spelling of 987731859409 in words is "nine hundred eighty-seven billion, seven hundred thirty-one million, eight hundred fifty-nine thousand, four hundred nine".