20368661 has 2 divisors, whose sum is σ = 20368662. Its totient is φ = 20368660.

The previous prime is 20368657. The next prime is 20368723. The reversal of 20368661 is 16686302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20340100 + 28561 = 4510^2 + 169^2 .

It is a cyclic number.

It is not a de Polignac number, because 20368661 - 2² = 20368657 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20368651) 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, 10184330 + 10184331.

It is an arithmetic number, because the mean of its divisors is an integer number (10184331).

Almost surely, 2^20368661 is an apocalyptic number.

It is an amenable number.

20368661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20368661 is an equidigital number, since it uses as much as digits as its factorization.

20368661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 20368661 is about 4513.1652972166. The cubic root of 20368661 is about 273.0994507674.

The spelling of 20368661 in words is "twenty million, three hundred sixty-eight thousand, six hundred sixty-one".