20309081 has 8 divisors (see below), whose sum is σ = 23022720. Its totient is φ = 17759952.

The previous prime is 20309071. The next prime is 20309087. The reversal of 20309081 is 18090302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20309081 - 2¹⁴ = 20292697 is a prime.

It is a super-2 number, since 2×20309081² = 824917542129122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20309087) 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 7 ways as a sum of consecutive naturals, for example, 40865 + ... + 41358.

It is an arithmetic number, because the mean of its divisors is an integer number (2877840).

Almost surely, 2^20309081 is an apocalyptic number.

It is an amenable number.

20309081 is a deficient number, since it is larger than the sum of its proper divisors (2713639).

20309081 is a wasteful number, since it uses less digits than its factorization.

20309081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82255.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 20309081 is about 4506.5597743734. The cubic root of 20309081 is about 272.8329113021.

Adding to 20309081 its reverse (18090302), we get a palindrome (38399383).

It can be divided in two parts, 2030 and 9081, that added together give a palindrome (11111).

The spelling of 20309081 in words is "twenty million, three hundred nine thousand, eighty-one".