78643963 has 2 divisors, whose sum is σ = 78643964. Its totient is φ = 78643962.

The previous prime is 78643951. The next prime is 78643967. The reversal of 78643963 is 36934687.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78643963 - 2¹⁷ = 78512891 is a prime.

It is not a weakly prime, because it can be changed into another prime (78643967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39321981 + 39321982.

It is an arithmetic number, because the mean of its divisors is an integer number (39321982).

Almost surely, 2^78643963 is an apocalyptic number.

78643963 is a deficient number, since it is larger than the sum of its proper divisors (1).

78643963 is an equidigital number, since it uses as much as digits as its factorization.

78643963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 46.

The square root of 78643963 is about 8868.1431540092. The cubic root of 78643963 is about 428.4384736203.

The spelling of 78643963 in words is "seventy-eight million, six hundred forty-three thousand, nine hundred sixty-three".