20039947 has 4 divisors (see below), whose sum is σ = 20056696. Its totient is φ = 20023200.

The previous prime is 20039933. The next prime is 20039953. The reversal of 20039947 is 74993002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20039947 - 2⁷ = 20039819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20009947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6429 + ... + 9022.

It is an arithmetic number, because the mean of its divisors is an integer number (5014174).

Almost surely, 2^20039947 is an apocalyptic number.

20039947 is a deficient number, since it is larger than the sum of its proper divisors (16749).

20039947 is a wasteful number, since it uses less digits than its factorization.

20039947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16748.

The product of its (nonzero) digits is 13608, while the sum is 34.

The square root of 20039947 is about 4476.5999374525. The cubic root of 20039947 is about 271.6223628724.

The spelling of 20039947 in words is "twenty million, thirty-nine thousand, nine hundred forty-seven".