8521198987 has 4 divisors (see below), whose sum is σ = 9738513136. Its totient is φ = 7303884840.

The previous prime is 8521198979. The next prime is 8521198993. The reversal of 8521198987 is 7898911258.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 8521198987 - 2³ = 8521198979 is a prime.

It is a super-2 number, since 2×8521198987² (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 (8521198957) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 608657064 + ... + 608657077.

It is an arithmetic number, because the mean of its divisors is an integer number (2434628284).

Almost surely, 2^8521198987 is an apocalyptic number.

8521198987 is a deficient number, since it is larger than the sum of its proper divisors (1217314149).

8521198987 is a wasteful number, since it uses less digits than its factorization.

8521198987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1217314148.

The product of its digits is 2903040, while the sum is 58.

The square root of 8521198987 is about 92310.3406287725. The cubic root of 8521198987 is about 2042.5227493949.

The spelling of 8521198987 in words is "eight billion, five hundred twenty-one million, one hundred ninety-eight thousand, nine hundred eighty-seven".