78257687 has 2 divisors, whose sum is σ = 78257688. Its totient is φ = 78257686.

The previous prime is 78257623. The next prime is 78257717. The reversal of 78257687 is 78675287.

It is a strong prime.

It is an emirp because it is prime and its reverse (78675287) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78257687 - 2⁶ = 78257623 is a prime.

It is a super-2 number, since 2×78257687² = 12248531149179938, 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 (78257087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39128843 + 39128844.

It is an arithmetic number, because the mean of its divisors is an integer number (39128844).

Almost surely, 2^78257687 is an apocalyptic number.

78257687 is a deficient number, since it is larger than the sum of its proper divisors (1).

78257687 is an equidigital number, since it uses as much as digits as its factorization.

78257687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1317120, while the sum is 50.

The square root of 78257687 is about 8846.3374907359. The cubic root of 78257687 is about 427.7358674682.

The spelling of 78257687 in words is "seventy-eight million, two hundred fifty-seven thousand, six hundred eighty-seven".