163078991 has 2 divisors, whose sum is σ = 163078992. Its totient is φ = 163078990.

The previous prime is 163078961. The next prime is 163078997. The reversal of 163078991 is 199870361.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 163078991 - 2¹⁸ = 162816847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (163078997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 81539495 + 81539496.

It is an arithmetic number, because the mean of its divisors is an integer number (81539496).

Almost surely, 2^163078991 is an apocalyptic number.

163078991 is a deficient number, since it is larger than the sum of its proper divisors (1).

163078991 is an equidigital number, since it uses as much as digits as its factorization.

163078991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 163078991 is about 12770.2384864183. The cubic root of 163078991 is about 546.3437826996.

The spelling of 163078991 in words is "one hundred sixty-three million, seventy-eight thousand, nine hundred ninety-one".