20709641 has 2 divisors, whose sum is σ = 20709642. Its totient is φ = 20709640.

The previous prime is 20709629. The next prime is 20709653. The reversal of 20709641 is 14690702.

It is a balanced prime because it is at equal distance from previous prime (20709629) and next prime (20709653).

It can be written as a sum of positive squares in only one way, i.e., 17397241 + 3312400 = 4171^2 + 1820^2 .

It is a cyclic number.

It is not a de Polignac number, because 20709641 - 2²² = 16515337 is a prime.

It is not a weakly prime, because it can be changed into another prime (20709671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10354820 + 10354821.

It is an arithmetic number, because the mean of its divisors is an integer number (10354821).

Almost surely, 2^20709641 is an apocalyptic number.

It is an amenable number.

20709641 is a deficient number, since it is larger than the sum of its proper divisors (1).

20709641 is an equidigital number, since it uses as much as digits as its factorization.

20709641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 29.

The square root of 20709641 is about 4550.7846576167. The cubic root of 20709641 is about 274.6149586565.

It can be divided in two parts, 2070 and 9641, that added together give a palindrome (11711).

The spelling of 20709641 in words is "twenty million, seven hundred nine thousand, six hundred forty-one".