7678664658 has 36 divisors (see below), whose sum is σ = 19353371310. Its totient is φ = 2193903936.

The previous prime is 7678664641. The next prime is 7678664663. The reversal of 7678664658 is 8564668767.

It can be written as a sum of positive squares in only one way, i.e., 6615056889 + 1063607769 = 81333^2 + 32613^2 .

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 7678664595 and 7678664604.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4352103 + ... + 4353866.

Almost surely, 2^7678664658 is an apocalyptic number.

7678664658 is an abundant number, since it is smaller than the sum of its proper divisors (11674706652).

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

7678664658 is a wasteful number, since it uses less digits than its factorization.

7678664658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8705991 (or 8705981 counting only the distinct ones).

The product of its digits is 81285120, while the sum is 63.

The square root of 7678664658 is about 87627.9901515492. The cubic root of 7678664658 is about 1972.8553043446.

The spelling of 7678664658 in words is "seven billion, six hundred seventy-eight million, six hundred sixty-four thousand, six hundred fifty-eight".