20659591 has 2 divisors, whose sum is σ = 20659592. Its totient is φ = 20659590.

The previous prime is 20659577. The next prime is 20659601. The reversal of 20659591 is 19595602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20659591 - 2¹¹ = 20657543 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20659591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20659501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10329795 + 10329796.

It is an arithmetic number, because the mean of its divisors is an integer number (10329796).

Almost surely, 2^20659591 is an apocalyptic number.

20659591 is a deficient number, since it is larger than the sum of its proper divisors (1).

20659591 is an equidigital number, since it uses as much as digits as its factorization.

20659591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24300, while the sum is 37.

The square root of 20659591 is about 4545.2822794630. The cubic root of 20659591 is about 274.3935550779.

The spelling of 20659591 in words is "twenty million, six hundred fifty-nine thousand, five hundred ninety-one".