20577691 has 2 divisors, whose sum is σ = 20577692. Its totient is φ = 20577690.

The previous prime is 20577673. The next prime is 20577721. The reversal of 20577691 is 19677502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20577691 - 2⁵ = 20577659 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20577691.

It is not a weakly prime, because it can be changed into another prime (20577631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10288845 + 10288846.

It is an arithmetic number, because the mean of its divisors is an integer number (10288846).

Almost surely, 2^20577691 is an apocalyptic number.

20577691 is a deficient number, since it is larger than the sum of its proper divisors (1).

20577691 is an equidigital number, since it uses as much as digits as its factorization.

20577691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26460, while the sum is 37.

The square root of 20577691 is about 4536.2639914361. The cubic root of 20577691 is about 274.0304857124.

The spelling of 20577691 in words is "twenty million, five hundred seventy-seven thousand, six hundred ninety-one".