20329891 has 4 divisors (see below), whose sum is σ = 20825784. Its totient is φ = 19834000.

The previous prime is 20329889. The next prime is 20329901. The reversal of 20329891 is 19892302.

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

It is a cyclic number.

It is not a de Polignac number, because 20329891 - 2¹ = 20329889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20329591) 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, 247885 + ... + 247966.

It is an arithmetic number, because the mean of its divisors is an integer number (5206446).

Almost surely, 2^20329891 is an apocalyptic number.

20329891 is a deficient number, since it is larger than the sum of its proper divisors (495893).

20329891 is an equidigital number, since it uses as much as digits as its factorization.

20329891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495892.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 20329891 is about 4508.8680397634. The cubic root of 20329891 is about 272.9260669165.

The spelling of 20329891 in words is "twenty million, three hundred twenty-nine thousand, eight hundred ninety-one".