20384947 has 4 divisors (see below), whose sum is σ = 22238136. Its totient is φ = 18531760.

The previous prime is 20384933. The next prime is 20384953. The reversal of 20384947 is 74948302.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20384947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20384927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 926578 + ... + 926599.

It is an arithmetic number, because the mean of its divisors is an integer number (5559534).

Almost surely, 2^20384947 is an apocalyptic number.

20384947 is a deficient number, since it is larger than the sum of its proper divisors (1853189).

20384947 is a wasteful number, since it uses less digits than its factorization.

20384947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1853188.

The product of its (nonzero) digits is 48384, while the sum is 37.

The square root of 20384947 is about 4514.9692136270. The cubic root of 20384947 is about 273.1722179918.

The spelling of 20384947 in words is "twenty million, three hundred eighty-four thousand, nine hundred forty-seven".