78734857 has 2 divisors, whose sum is σ = 78734858. Its totient is φ = 78734856.

The previous prime is 78734791. The next prime is 78734863. The reversal of 78734857 is 75843787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66928761 + 11806096 = 8181^2 + 3436^2 .

It is a cyclic number.

It is not a de Polignac number, because 78734857 - 2¹¹ = 78732809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78734857.

It is not a weakly prime, because it can be changed into another prime (78734867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39367428 + 39367429.

It is an arithmetic number, because the mean of its divisors is an integer number (39367429).

Almost surely, 2^78734857 is an apocalyptic number.

It is an amenable number.

78734857 is a deficient number, since it is larger than the sum of its proper divisors (1).

78734857 is an equidigital number, since it uses as much as digits as its factorization.

78734857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1317120, while the sum is 49.

The square root of 78734857 is about 8873.2664222371. The cubic root of 78734857 is about 428.6034682449.

The spelling of 78734857 in words is "seventy-eight million, seven hundred thirty-four thousand, eight hundred fifty-seven".