159821591 has 2 divisors, whose sum is σ = 159821592. Its totient is φ = 159821590.

The previous prime is 159821587. The next prime is 159821609. The reversal of 159821591 is 195128951.

It is a weak prime.

It is an emirp because it is prime and its reverse (195128951) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 159821591 - 2² = 159821587 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (159821551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79910795 + 79910796.

It is an arithmetic number, because the mean of its divisors is an integer number (79910796).

Almost surely, 2^159821591 is an apocalyptic number.

159821591 is a deficient number, since it is larger than the sum of its proper divisors (1).

159821591 is an equidigital number, since it uses as much as digits as its factorization.

159821591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32400, while the sum is 41.

The square root of 159821591 is about 12642.0564387286. The cubic root of 159821591 is about 542.6816663845.

The spelling of 159821591 in words is "one hundred fifty-nine million, eight hundred twenty-one thousand, five hundred ninety-one".