20196591 has 4 divisors (see below), whose sum is σ = 26928792. Its totient is φ = 13464392.

The previous prime is 20196577. The next prime is 20196607. The reversal of 20196591 is 19569102.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20196591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20196521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3366096 + ... + 3366101.

It is an arithmetic number, because the mean of its divisors is an integer number (6732198).

Almost surely, 2^20196591 is an apocalyptic number.

20196591 is a deficient number, since it is larger than the sum of its proper divisors (6732201).

20196591 is an equidigital number, since it uses as much as digits as its factorization.

20196591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6732200.

The product of its (nonzero) digits is 4860, while the sum is 33.

The square root of 20196591 is about 4494.0617485744. The cubic root of 20196591 is about 272.3282468457.

The spelling of 20196591 in words is "twenty million, one hundred ninety-six thousand, five hundred ninety-one".