20006881 has 2 divisors, whose sum is σ = 20006882. Its totient is φ = 20006880.

The previous prime is 20006869. The next prime is 20006887. The reversal of 20006881 is 18860002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14318656 + 5688225 = 3784^2 + 2385^2 .

It is a cyclic number.

It is not a de Polignac number, because 20006881 - 2¹¹ = 20004833 is a prime.

It is a super-2 number, since 2×20006881² = 800550574696322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20006887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10003440 + 10003441.

It is an arithmetic number, because the mean of its divisors is an integer number (10003441).

Almost surely, 2^20006881 is an apocalyptic number.

It is an amenable number.

20006881 is a deficient number, since it is larger than the sum of its proper divisors (1).

20006881 is an equidigital number, since it uses as much as digits as its factorization.

20006881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 20006881 is about 4472.9052080276. The cubic root of 20006881 is about 271.4728879361.

Adding to 20006881 its reverse (18860002), we get a palindrome (38866883).

The spelling of 20006881 in words is "twenty million, six thousand, eight hundred eighty-one".