78779047 has 2 divisors, whose sum is σ = 78779048. Its totient is φ = 78779046.

The previous prime is 78779039. The next prime is 78779059. The reversal of 78779047 is 74097787.

It is a weak prime.

It is an emirp because it is prime and its reverse (74097787) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78779047 - 2³ = 78779039 is a prime.

It is a super-2 number, since 2×78779047² = 12412276492456418, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78779017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39389523 + 39389524.

It is an arithmetic number, because the mean of its divisors is an integer number (39389524).

Almost surely, 2^78779047 is an apocalyptic number.

78779047 is a deficient number, since it is larger than the sum of its proper divisors (1).

78779047 is an equidigital number, since it uses as much as digits as its factorization.

78779047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 691488, while the sum is 49.

The square root of 78779047 is about 8875.7561368032. The cubic root of 78779047 is about 428.6836379255.

The spelling of 78779047 in words is "seventy-eight million, seven hundred seventy-nine thousand, forty-seven".