20773661 has 2 divisors, whose sum is σ = 20773662. Its totient is φ = 20773660.

The previous prime is 20773651. The next prime is 20773663. The reversal of 20773661 is 16637702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15960025 + 4813636 = 3995^2 + 2194^2 .

It is a cyclic number.

It is not a de Polignac number, because 20773661 - 2¹⁴ = 20757277 is a prime.

Together with 20773663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20773663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10386830 + 10386831.

It is an arithmetic number, because the mean of its divisors is an integer number (10386831).

Almost surely, 2^20773661 is an apocalyptic number.

It is an amenable number.

20773661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20773661 is an equidigital number, since it uses as much as digits as its factorization.

20773661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10584, while the sum is 32.

The square root of 20773661 is about 4557.8131817792. The cubic root of 20773661 is about 274.8976412442.

The spelling of 20773661 in words is "twenty million, seven hundred seventy-three thousand, six hundred sixty-one".