78542617 has 2 divisors, whose sum is σ = 78542618. Its totient is φ = 78542616.

The previous prime is 78542609. The next prime is 78542627. The reversal of 78542617 is 71624587.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71301136 + 7241481 = 8444^2 + 2691^2 .

It is a cyclic number.

It is not a de Polignac number, because 78542617 - 2³ = 78542609 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78542617.

It is not a weakly prime, because it can be changed into another prime (78542627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39271308 + 39271309.

It is an arithmetic number, because the mean of its divisors is an integer number (39271309).

Almost surely, 2^78542617 is an apocalyptic number.

It is an amenable number.

78542617 is a deficient number, since it is larger than the sum of its proper divisors (1).

78542617 is an equidigital number, since it uses as much as digits as its factorization.

78542617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 94080, while the sum is 40.

The square root of 78542617 is about 8862.4272634533. The cubic root of 78542617 is about 428.2543561165.

The spelling of 78542617 in words is "seventy-eight million, five hundred forty-two thousand, six hundred seventeen".