20707081 has 2 divisors, whose sum is σ = 20707082. Its totient is φ = 20707080.

The previous prime is 20707069. The next prime is 20707097. The reversal of 20707081 is 18070702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20611600 + 95481 = 4540^2 + 309^2 .

It is a cyclic number.

It is not a de Polignac number, because 20707081 - 2¹⁷ = 20576009 is a prime.

It is a super-2 number, since 2×20707081² = 857566407081122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20707021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10353540 + 10353541.

It is an arithmetic number, because the mean of its divisors is an integer number (10353541).

Almost surely, 2^20707081 is an apocalyptic number.

It is an amenable number.

20707081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20707081 is an equidigital number, since it uses as much as digits as its factorization.

20707081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 784, while the sum is 25.

The square root of 20707081 is about 4550.5033787483. The cubic root of 20707081 is about 274.6036427793.

Adding to 20707081 its reverse (18070702), we get a palindrome (38777783).

The spelling of 20707081 in words is "twenty million, seven hundred seven thousand, eighty-one".