78915247 has 2 divisors, whose sum is σ = 78915248. Its totient is φ = 78915246.

The previous prime is 78915229. The next prime is 78915253. The reversal of 78915247 is 74251987.

It is a strong prime.

It is an emirp because it is prime and its reverse (74251987) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78915247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78915257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39457623 + 39457624.

It is an arithmetic number, because the mean of its divisors is an integer number (39457624).

Almost surely, 2^78915247 is an apocalyptic number.

78915247 is a deficient number, since it is larger than the sum of its proper divisors (1).

78915247 is an equidigital number, since it uses as much as digits as its factorization.

78915247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 141120, while the sum is 43.

The square root of 78915247 is about 8883.4254091538. The cubic root of 78915247 is about 428.9305440847.

The spelling of 78915247 in words is "seventy-eight million, nine hundred fifteen thousand, two hundred forty-seven".