20680831 has 2 divisors, whose sum is σ = 20680832. Its totient is φ = 20680830.

The previous prime is 20680811. The next prime is 20680843. The reversal of 20680831 is 13808602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20680831 - 2¹⁵ = 20648063 is a prime.

It is a super-2 number, since 2×20680831² = 855393541701122, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20680831.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20680811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10340415 + 10340416.

It is an arithmetic number, because the mean of its divisors is an integer number (10340416).

Almost surely, 2^20680831 is an apocalyptic number.

20680831 is a deficient number, since it is larger than the sum of its proper divisors (1).

20680831 is an equidigital number, since it uses as much as digits as its factorization.

20680831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 20680831 is about 4547.6181677885. The cubic root of 20680831 is about 274.4875569867.

The spelling of 20680831 in words is "twenty million, six hundred eighty thousand, eight hundred thirty-one".