20839867 has 2 divisors, whose sum is σ = 20839868. Its totient is φ = 20839866.

The previous prime is 20839829. The next prime is 20839879. The reversal of 20839867 is 76893802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20839867 - 2¹¹ = 20837819 is a prime.

It is not a weakly prime, because it can be changed into another prime (20839267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10419933 + 10419934.

It is an arithmetic number, because the mean of its divisors is an integer number (10419934).

Almost surely, 2^20839867 is an apocalyptic number.

20839867 is a deficient number, since it is larger than the sum of its proper divisors (1).

20839867 is an equidigital number, since it uses as much as digits as its factorization.

20839867 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 20839867 is about 4565.0703170926. The cubic root of 20839867 is about 275.1893659907.

The spelling of 20839867 in words is "twenty million, eight hundred thirty-nine thousand, eight hundred sixty-seven".