20489191 has 2 divisors, whose sum is σ = 20489192. Its totient is φ = 20489190.

The previous prime is 20489177. The next prime is 20489221. The reversal of 20489191 is 19198402.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20489191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20489101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10244595 + 10244596.

It is an arithmetic number, because the mean of its divisors is an integer number (10244596).

Almost surely, 2^20489191 is an apocalyptic number.

20489191 is a deficient number, since it is larger than the sum of its proper divisors (1).

20489191 is an equidigital number, since it uses as much as digits as its factorization.

20489191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 20489191 is about 4526.4987573178. The cubic root of 20489191 is about 273.6370734434.

The spelling of 20489191 in words is "twenty million, four hundred eighty-nine thousand, one hundred ninety-one".