8917978509 has 48 divisors (see below), whose sum is σ = 14307441408. Its totient is φ = 5307120000.

The previous prime is 8917978477. The next prime is 8917978513. The reversal of 8917978509 is 9058797198.

It is not a de Polignac number, because 8917978509 - 2⁵ = 8917978477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8917978549) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5500719 + ... + 5502339.

It is an arithmetic number, because the mean of its divisors is an integer number (298071696).

Almost surely, 2^8917978509 is an apocalyptic number.

It is an amenable number.

8917978509 is a deficient number, since it is larger than the sum of its proper divisors (5389462899).

8917978509 is a wasteful number, since it uses less digits than its factorization.

8917978509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2610 (or 2607 counting only the distinct ones).

The product of its (nonzero) digits is 11430720, while the sum is 63.

The square root of 8917978509 is about 94435.0491554910. The cubic root of 8917978509 is about 2073.7455820805.

The spelling of 8917978509 in words is "eight billion, nine hundred seventeen million, nine hundred seventy-eight thousand, five hundred nine".