20844661 has 2 divisors, whose sum is σ = 20844662. Its totient is φ = 20844660.

The previous prime is 20844623. The next prime is 20844667. The reversal of 20844661 is 16644802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20520900 + 323761 = 4530^2 + 569^2 .

It is a cyclic number.

It is not a de Polignac number, because 20844661 - 2⁹ = 20844149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20844667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10422330 + 10422331.

It is an arithmetic number, because the mean of its divisors is an integer number (10422331).

Almost surely, 2^20844661 is an apocalyptic number.

It is an amenable number.

20844661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20844661 is an equidigital number, since it uses as much as digits as its factorization.

20844661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 20844661 is about 4565.5953609579. The cubic root of 20844661 is about 275.2104658802.

The spelling of 20844661 in words is "twenty million, eight hundred forty-four thousand, six hundred sixty-one".