78816971 has 2 divisors, whose sum is σ = 78816972. Its totient is φ = 78816970.

The previous prime is 78816931. The next prime is 78817003. The reversal of 78816971 is 17961887.

It is a strong prime.

It is an emirp because it is prime and its reverse (17961887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78816971 - 2²⁶ = 11708107 is a prime.

It is a super-2 number, since 2×78816971² = 12424229835229682, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78816901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39408485 + 39408486.

It is an arithmetic number, because the mean of its divisors is an integer number (39408486).

Almost surely, 2^78816971 is an apocalyptic number.

78816971 is a deficient number, since it is larger than the sum of its proper divisors (1).

78816971 is an equidigital number, since it uses as much as digits as its factorization.

78816971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 169344, while the sum is 47.

The square root of 78816971 is about 8877.8922611169. The cubic root of 78816971 is about 428.7524159015.

The spelling of 78816971 in words is "seventy-eight million, eight hundred sixteen thousand, nine hundred seventy-one".