78660997 has 4 divisors (see below), whose sum is σ = 79424800. Its totient is φ = 77897196.

The previous prime is 78660979. The next prime is 78661031. The reversal of 78660997 is 79906687.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78660997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78660917) 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, 381747 + ... + 381952.

It is an arithmetic number, because the mean of its divisors is an integer number (19856200).

Almost surely, 2^78660997 is an apocalyptic number.

It is an amenable number.

78660997 is a deficient number, since it is larger than the sum of its proper divisors (763803).

78660997 is a wasteful number, since it uses less digits than its factorization.

78660997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 763802.

The product of its (nonzero) digits is 1143072, while the sum is 52.

The square root of 78660997 is about 8869.1035059920. The cubic root of 78660997 is about 428.4694041323.

The spelling of 78660997 in words is "seventy-eight million, six hundred sixty thousand, nine hundred ninety-seven".