158809991 has 2 divisors, whose sum is σ = 158809992. Its totient is φ = 158809990.

The previous prime is 158809979. The next prime is 158809997. The reversal of 158809991 is 199908851.

It is a strong prime.

It is an emirp because it is prime and its reverse (199908851) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-158809991 is a prime.

It is a super-2 number, since 2×158809991² = 50441226482840162, 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 (158809997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79404995 + 79404996.

It is an arithmetic number, because the mean of its divisors is an integer number (79404996).

Almost surely, 2^158809991 is an apocalyptic number.

158809991 is a deficient number, since it is larger than the sum of its proper divisors (1).

158809991 is an equidigital number, since it uses as much as digits as its factorization.

158809991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 233280, while the sum is 50.

The square root of 158809991 is about 12601.9836137015. The cubic root of 158809991 is about 541.5342637911.

The spelling of 158809991 in words is "one hundred fifty-eight million, eight hundred nine thousand, nine hundred ninety-one".