78111899 has 2 divisors, whose sum is σ = 78111900. Its totient is φ = 78111898.

The previous prime is 78111863. The next prime is 78111911. The reversal of 78111899 is 99811187.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78111899 - 2⁸ = 78111643 is a prime.

It is a super-2 number, since 2×78111899² = 12202937530772402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78111199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39055949 + 39055950.

It is an arithmetic number, because the mean of its divisors is an integer number (39055950).

Almost surely, 2^78111899 is an apocalyptic number.

78111899 is a deficient number, since it is larger than the sum of its proper divisors (1).

78111899 is an equidigital number, since it uses as much as digits as its factorization.

78111899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 44.

The square root of 78111899 is about 8838.0936292845. The cubic root of 78111899 is about 427.4700894455.

The spelling of 78111899 in words is "seventy-eight million, one hundred eleven thousand, eight hundred ninety-nine".