20528591 has 2 divisors, whose sum is σ = 20528592. Its totient is φ = 20528590.

The previous prime is 20528567. The next prime is 20528593. The reversal of 20528591 is 19582502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20528591 - 2¹⁰ = 20527567 is a prime.

Together with 20528593, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20528593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10264295 + 10264296.

It is an arithmetic number, because the mean of its divisors is an integer number (10264296).

Almost surely, 2^20528591 is an apocalyptic number.

20528591 is a deficient number, since it is larger than the sum of its proper divisors (1).

20528591 is an equidigital number, since it uses as much as digits as its factorization.

20528591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 20528591 is about 4530.8488167230. The cubic root of 20528591 is about 273.8123593194.

The spelling of 20528591 in words is "twenty million, five hundred twenty-eight thousand, five hundred ninety-one".