998138215287 has 24 divisors (see below), whose sum is σ = 1474460869440. Its totient is φ = 650497348800.

The previous prime is 998138215253. The next prime is 998138215289. The reversal of 998138215287 is 782512831899.

998138215287 is a `hidden beast` number, since 9 + 9 + 8 + 138 + 215 + 287 = 666.

It is not a de Polignac number, because 998138215287 - 2⁶ = 998138215223 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998138215289) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6877948 + ... + 7021569.

It is an arithmetic number, because the mean of its divisors is an integer number (61435869560).

Almost surely, 2^998138215287 is an apocalyptic number.

998138215287 is a deficient number, since it is larger than the sum of its proper divisors (476322654153).

998138215287 is a wasteful number, since it uses less digits than its factorization.

998138215287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13899703 (or 13899700 counting only the distinct ones).

The product of its digits is 17418240, while the sum is 63.

The spelling of 998138215287 in words is "nine hundred ninety-eight billion, one hundred thirty-eight million, two hundred fifteen thousand, two hundred eighty-seven".