78155077919 has 2 divisors, whose sum is σ = 78155077920. Its totient is φ = 78155077918.

The previous prime is 78155077787. The next prime is 78155077921. The reversal of 78155077919 is 91977055187.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78155077919 is a prime.

It is a super-2 number, since 2×78155077919² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 78155077921, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78155077019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39077538959 + 39077538960.

It is an arithmetic number, because the mean of its divisors is an integer number (39077538960).

Almost surely, 2^78155077919 is an apocalyptic number.

78155077919 is a deficient number, since it is larger than the sum of its proper divisors (1).

78155077919 is an equidigital number, since it uses as much as digits as its factorization.

78155077919 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5556600, while the sum is 59.

The spelling of 78155077919 in words is "seventy-eight billion, one hundred fifty-five million, seventy-seven thousand, nine hundred nineteen".