78340778387 has 2 divisors, whose sum is σ = 78340778388. Its totient is φ = 78340778386.

The previous prime is 78340778323. The next prime is 78340778393. The reversal of 78340778387 is 78387704387.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78340778387 - 2⁶ = 78340778323 is a prime.

It is a super-2 number, since 2×78340778387² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78340778287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39170389193 + 39170389194.

It is an arithmetic number, because the mean of its divisors is an integer number (39170389194).

Almost surely, 2^78340778387 is an apocalyptic number.

78340778387 is a deficient number, since it is larger than the sum of its proper divisors (1).

78340778387 is an equidigital number, since it uses as much as digits as its factorization.

78340778387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 44255232, while the sum is 62.

The spelling of 78340778387 in words is "seventy-eight billion, three hundred forty million, seven hundred seventy-eight thousand, three hundred eighty-seven".