78604891 has 2 divisors, whose sum is σ = 78604892. Its totient is φ = 78604890.

The previous prime is 78604853. The next prime is 78604907. The reversal of 78604891 is 19840687.

It is a strong prime.

It is an emirp because it is prime and its reverse (19840687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78604891 - 2¹⁹ = 78080603 is a prime.

It is not a weakly prime, because it can be changed into another prime (78604291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39302445 + 39302446.

It is an arithmetic number, because the mean of its divisors is an integer number (39302446).

Almost surely, 2^78604891 is an apocalyptic number.

78604891 is a deficient number, since it is larger than the sum of its proper divisors (1).

78604891 is an equidigital number, since it uses as much as digits as its factorization.

78604891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 78604891 is about 8865.9399388897. The cubic root of 78604891 is about 428.3675094063.

The spelling of 78604891 in words is "seventy-eight million, six hundred four thousand, eight hundred ninety-one".