20445191 has 8 divisors (see below), whose sum is σ = 22233120. Its totient is φ = 18688032.

The previous prime is 20445181. The next prime is 20445193. The reversal of 20445191 is 19154402.

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 20445191 - 2¹⁸ = 20183047 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20445191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20445193) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6296 + ... + 8973.

It is an arithmetic number, because the mean of its divisors is an integer number (2779140).

Almost surely, 2^20445191 is an apocalyptic number.

20445191 is a deficient number, since it is larger than the sum of its proper divisors (1787929).

20445191 is a wasteful number, since it uses less digits than its factorization.

20445191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15385.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 20445191 is about 4521.6358765385. The cubic root of 20445191 is about 273.4410569181.

Adding to 20445191 its reverse (19154402), we get a palindrome (39599593).

The spelling of 20445191 in words is "twenty million, four hundred forty-five thousand, one hundred ninety-one".