20746021 has 2 divisors, whose sum is σ = 20746022. Its totient is φ = 20746020.

The previous prime is 20746013. The next prime is 20746027. The reversal of 20746021 is 12064702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20349121 + 396900 = 4511^2 + 630^2 .

It is a cyclic number.

It is not a de Polignac number, because 20746021 - 2³ = 20746013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20745983 and 20746001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20746027) 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, 10373010 + 10373011.

It is an arithmetic number, because the mean of its divisors is an integer number (10373011).

Almost surely, 2^20746021 is an apocalyptic number.

It is an amenable number.

20746021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20746021 is an equidigital number, since it uses as much as digits as its factorization.

20746021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 20746021 is about 4554.7800166419. The cubic root of 20746021 is about 274.7756671867.

The spelling of 20746021 in words is "twenty million, seven hundred forty-six thousand, twenty-one".