6516899778 has 32 divisors (see below), whose sum is σ = 13532016960. Its totient is φ = 2089805760.

The previous prime is 6516899761. The next prime is 6516899783. The reversal of 6516899778 is 8779986156.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19408 + ... + 115803.

It is an arithmetic number, because the mean of its divisors is an integer number (422875530).

Almost surely, 2^6516899778 is an apocalyptic number.

6516899778 is an abundant number, since it is smaller than the sum of its proper divisors (7015117182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6516899778 is a wasteful number, since it uses less digits than its factorization.

6516899778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135522.

The product of its digits is 45722880, while the sum is 66.

The square root of 6516899778 is about 80727.3174210564. The cubic root of 6516899778 is about 1867.8715789560.

The spelling of 6516899778 in words is "six billion, five hundred sixteen million, eight hundred ninety-nine thousand, seven hundred seventy-eight".