78581911 has 2 divisors, whose sum is σ = 78581912. Its totient is φ = 78581910.

The previous prime is 78581903. The next prime is 78581917. The reversal of 78581911 is 11918587.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78581911 - 2³ = 78581903 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78581917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39290955 + 39290956.

It is an arithmetic number, because the mean of its divisors is an integer number (39290956).

Almost surely, 2^78581911 is an apocalyptic number.

78581911 is a deficient number, since it is larger than the sum of its proper divisors (1).

78581911 is an equidigital number, since it uses as much as digits as its factorization.

78581911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 40.

The square root of 78581911 is about 8864.6438732755. The cubic root of 78581911 is about 428.3257611780.

The spelling of 78581911 in words is "seventy-eight million, five hundred eighty-one thousand, nine hundred eleven".