20681166619 has 2 divisors, whose sum is σ = 20681166620. Its totient is φ = 20681166618.

The previous prime is 20681166599. The next prime is 20681166637. The reversal of 20681166619 is 91666118602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20681166619 - 2⁷ = 20681166491 is a prime.

It is a super-2 number, since 2×20681166619² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20681166419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10340583309 + 10340583310.

It is an arithmetic number, because the mean of its divisors is an integer number (10340583310).

Almost surely, 2^20681166619 is an apocalyptic number.

20681166619 is a deficient number, since it is larger than the sum of its proper divisors (1).

20681166619 is an equidigital number, since it uses as much as digits as its factorization.

20681166619 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 46.

It can be divided in two parts, 206811 and 66619, that added together give a triangular number (273430 = T₇₃₉).

The spelling of 20681166619 in words is "twenty billion, six hundred eighty-one million, one hundred sixty-six thousand, six hundred nineteen".