20159081 has 4 divisors (see below), whose sum is σ = 20168064. Its totient is φ = 20150100.

The previous prime is 20159047. The next prime is 20159107. The reversal of 20159081 is 18095102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20159081 is a prime.

It is a super-2 number, since 2×20159081² = 812777093529122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20159081.

It is not an unprimeable number, because it can be changed into a prime (20159281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2096 + ... + 6686.

It is an arithmetic number, because the mean of its divisors is an integer number (5042016).

Almost surely, 2^20159081 is an apocalyptic number.

It is an amenable number.

20159081 is a deficient number, since it is larger than the sum of its proper divisors (8983).

20159081 is an equidigital number, since it uses as much as digits as its factorization.

20159081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8982.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 20159081 is about 4489.8865241785. The cubic root of 20159081 is about 272.1595490193.

The spelling of 20159081 in words is "twenty million, one hundred fifty-nine thousand, eighty-one".