20500591 has 2 divisors, whose sum is σ = 20500592. Its totient is φ = 20500590.

The previous prime is 20500577. The next prime is 20500619. The reversal of 20500591 is 19500502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20500591 - 2¹³ = 20492399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20500511) 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 as a sum of consecutive naturals, namely, 10250295 + 10250296.

It is an arithmetic number, because the mean of its divisors is an integer number (10250296).

Almost surely, 2^20500591 is an apocalyptic number.

20500591 is a deficient number, since it is larger than the sum of its proper divisors (1).

20500591 is an equidigital number, since it uses as much as digits as its factorization.

20500591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 20500591 is about 4527.7578336302. The cubic root of 20500591 is about 273.6878137625.

The spelling of 20500591 in words is "twenty million, five hundred thousand, five hundred ninety-one".