78669617 has 8 divisors (see below), whose sum is σ = 84977256. Its totient is φ = 72398592.

The previous prime is 78669601. The next prime is 78669623. The reversal of 78669617 is 71696687.

It can be written as a sum of positive squares in 4 ways, for example, as 15689521 + 62980096 = 3961^2 + 7936^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78669617 - 2⁴ = 78669601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78663617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4598 + ... + 13359.

It is an arithmetic number, because the mean of its divisors is an integer number (10622157).

Almost surely, 2^78669617 is an apocalyptic number.

It is an amenable number.

78669617 is a deficient number, since it is larger than the sum of its proper divisors (6307639).

78669617 is a wasteful number, since it uses less digits than its factorization.

78669617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18307.

The product of its digits is 762048, while the sum is 50.

The square root of 78669617 is about 8869.5894493488. The cubic root of 78669617 is about 428.4850547152.

The spelling of 78669617 in words is "seventy-eight million, six hundred sixty-nine thousand, six hundred seventeen".