20680139 has 2 divisors, whose sum is σ = 20680140. Its totient is φ = 20680138.

The previous prime is 20680133. The next prime is 20680181. The reversal of 20680139 is 93108602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20680139 is a prime.

It is not a weakly prime, because it can be changed into another prime (20680133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10340069 + 10340070.

It is an arithmetic number, because the mean of its divisors is an integer number (10340070).

Almost surely, 2^20680139 is an apocalyptic number.

20680139 is a deficient number, since it is larger than the sum of its proper divisors (1).

20680139 is an equidigital number, since it uses as much as digits as its factorization.

20680139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 20680139 is about 4547.5420833677. The cubic root of 20680139 is about 274.4844954155.

The spelling of 20680139 in words is "twenty million, six hundred eighty thousand, one hundred thirty-nine".