78255643 has 2 divisors, whose sum is σ = 78255644. Its totient is φ = 78255642.

The previous prime is 78255581. The next prime is 78255649. The reversal of 78255643 is 34655287.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78255643 is a prime.

It is a super-2 number, since 2×78255643² = 12247891322686898, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78255596 and 78255605.

It is not a weakly prime, because it can be changed into another prime (78255649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39127821 + 39127822.

It is an arithmetic number, because the mean of its divisors is an integer number (39127822).

Almost surely, 2^78255643 is an apocalyptic number.

78255643 is a deficient number, since it is larger than the sum of its proper divisors (1).

78255643 is an equidigital number, since it uses as much as digits as its factorization.

78255643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 201600, while the sum is 40.

The square root of 78255643 is about 8846.2219619451. The cubic root of 78255643 is about 427.7321434476.

The spelling of 78255643 in words is "seventy-eight million, two hundred fifty-five thousand, six hundred forty-three".