20017939 has 2 divisors, whose sum is σ = 20017940. Its totient is φ = 20017938.

The previous prime is 20017937. The next prime is 20017951. The reversal of 20017939 is 93971002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20017939 - 2¹ = 20017937 is a prime.

Together with 20017937, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20017939.

It is not a weakly prime, because it can be changed into another prime (20017937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10008969 + 10008970.

It is an arithmetic number, because the mean of its divisors is an integer number (10008970).

Almost surely, 2^20017939 is an apocalyptic number.

20017939 is a deficient number, since it is larger than the sum of its proper divisors (1).

20017939 is an equidigital number, since it uses as much as digits as its factorization.

20017939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 20017939 is about 4474.1411466336. The cubic root of 20017939 is about 271.5228939698.

The spelling of 20017939 in words is "twenty million, seventeen thousand, nine hundred thirty-nine".