78842563 has 2 divisors, whose sum is σ = 78842564. Its totient is φ = 78842562.

The previous prime is 78842557. The next prime is 78842587. The reversal of 78842563 is 36524887.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78842563 - 2⁵ = 78842531 is a prime.

It is a super-2 number, since 2×78842563² = 12432299480817938, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78842593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39421281 + 39421282.

It is an arithmetic number, because the mean of its divisors is an integer number (39421282).

Almost surely, 2^78842563 is an apocalyptic number.

78842563 is a deficient number, since it is larger than the sum of its proper divisors (1).

78842563 is an equidigital number, since it uses as much as digits as its factorization.

78842563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 322560, while the sum is 43.

The square root of 78842563 is about 8879.3334772380. Note that the first 3 decimals coincide. The cubic root of 78842563 is about 428.7988164178.

The spelling of 78842563 in words is "seventy-eight million, eight hundred forty-two thousand, five hundred sixty-three".