78531779 has 2 divisors, whose sum is σ = 78531780. Its totient is φ = 78531778.

The previous prime is 78531727. The next prime is 78531781. The reversal of 78531779 is 97713587.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78531779 - 2¹⁶ = 78466243 is a prime.

Together with 78531781, it forms a pair of twin primes.

It is a Chen prime.

It is a pancake number, because a pancake can be divided into 78531779 parts by 12532 straight cuts.

It is not a weakly prime, because it can be changed into another prime (78531799) 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, 39265889 + 39265890.

It is an arithmetic number, because the mean of its divisors is an integer number (39265890).

Almost surely, 2^78531779 is an apocalyptic number.

78531779 is a deficient number, since it is larger than the sum of its proper divisors (1).

78531779 is an equidigital number, since it uses as much as digits as its factorization.

78531779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 370440, while the sum is 47.

The square root of 78531779 is about 8861.8157845895. The cubic root of 78531779 is about 428.2346571115.

The spelling of 78531779 in words is "seventy-eight million, five hundred thirty-one thousand, seven hundred seventy-nine".