20886661 has 2 divisors, whose sum is σ = 20886662. Its totient is φ = 20886660.

The previous prime is 20886637. The next prime is 20886683. The reversal of 20886661 is 16668802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14976900 + 5909761 = 3870^2 + 2431^2 .

It is a cyclic number.

It is not a de Polignac number, because 20886661 - 2⁵ = 20886629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20886661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20886601) 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, 10443330 + 10443331.

It is an arithmetic number, because the mean of its divisors is an integer number (10443331).

Almost surely, 2^20886661 is an apocalyptic number.

It is an amenable number.

20886661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20886661 is an equidigital number, since it uses as much as digits as its factorization.

20886661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 20886661 is about 4570.1926655230. The cubic root of 20886661 is about 275.3951828033.

The spelling of 20886661 in words is "twenty million, eight hundred eighty-six thousand, six hundred sixty-one".