20939641 has 2 divisors, whose sum is σ = 20939642. Its totient is φ = 20939640.

The previous prime is 20939627. The next prime is 20939647. The reversal of 20939641 is 14693902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14288400 + 6651241 = 3780^2 + 2579^2 .

It is a cyclic number.

It is not a de Polignac number, because 20939641 - 2⁵ = 20939609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20939597 and 20939606.

It is not a weakly prime, because it can be changed into another prime (20939647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10469820 + 10469821.

It is an arithmetic number, because the mean of its divisors is an integer number (10469821).

Almost surely, 2^20939641 is an apocalyptic number.

It is an amenable number.

20939641 is a deficient number, since it is larger than the sum of its proper divisors (1).

20939641 is an equidigital number, since it uses as much as digits as its factorization.

20939641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 20939641 is about 4575.9852491021. The cubic root of 20939641 is about 275.6278371545.

The spelling of 20939641 in words is "twenty million, nine hundred thirty-nine thousand, six hundred forty-one".