20768081 has 2 divisors, whose sum is σ = 20768082. Its totient is φ = 20768080.

The previous prime is 20768071. The next prime is 20768113. The reversal of 20768081 is 18086702.

It is an a-pointer prime, because the next prime (20768113) can be obtained adding 20768081 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15928081 + 4840000 = 3991^2 + 2200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20768081 is a prime.

It is a super-2 number, since 2×20768081² = 862626376845122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20768021) 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, 10384040 + 10384041.

It is an arithmetic number, because the mean of its divisors is an integer number (10384041).

Almost surely, 2^20768081 is an apocalyptic number.

It is an amenable number.

20768081 is a deficient number, since it is larger than the sum of its proper divisors (1).

20768081 is an equidigital number, since it uses as much as digits as its factorization.

20768081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 20768081 is about 4557.2010050030. The cubic root of 20768081 is about 274.8730256794.

The spelling of 20768081 in words is "twenty million, seven hundred sixty-eight thousand, eighty-one".