78898591 has 2 divisors, whose sum is σ = 78898592. Its totient is φ = 78898590.

The previous prime is 78898577. The next prime is 78898601. The reversal of 78898591 is 19589887.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78898591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78898511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39449295 + 39449296.

It is an arithmetic number, because the mean of its divisors is an integer number (39449296).

Almost surely, 2^78898591 is an apocalyptic number.

78898591 is a deficient number, since it is larger than the sum of its proper divisors (1).

78898591 is an equidigital number, since it uses as much as digits as its factorization.

78898591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1451520, while the sum is 55.

The square root of 78898591 is about 8882.4878834705. The cubic root of 78898591 is about 428.9003649998.

The spelling of 78898591 in words is "seventy-eight million, eight hundred ninety-eight thousand, five hundred ninety-one".