159097781 has 4 divisors (see below), whose sum is σ = 168456492. Its totient is φ = 149739072.

The previous prime is 159097711. The next prime is 159097793. The reversal of 159097781 is 187790951.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 75082225 + 84015556 = 8665^2 + 9166^2 .

It is a cyclic number.

It is not a de Polignac number, because 159097781 - 2¹⁴ = 159081397 is a prime.

It is a super-2 number, since 2×159097781² = 50624207838247922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (159097711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4679330 + ... + 4679363.

It is an arithmetic number, because the mean of its divisors is an integer number (42114123).

Almost surely, 2^159097781 is an apocalyptic number.

It is an amenable number.

159097781 is a deficient number, since it is larger than the sum of its proper divisors (9358711).

159097781 is an equidigital number, since it uses as much as digits as its factorization.

159097781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9358710.

The product of its (nonzero) digits is 158760, while the sum is 47.

The square root of 159097781 is about 12613.3968858512. The cubic root of 159097781 is about 541.8611829784.

The spelling of 159097781 in words is "one hundred fifty-nine million, ninety-seven thousand, seven hundred eighty-one".