20305947 has 8 divisors (see below), whose sum is σ = 27735120. Its totient is φ = 13207040.

The previous prime is 20305931. The next prime is 20305951. The reversal of 20305947 is 74950302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20305947 - 2⁴ = 20305931 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20305907) 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 7 ways as a sum of consecutive naturals, for example, 82422 + ... + 82667.

It is an arithmetic number, because the mean of its divisors is an integer number (3466890).

Almost surely, 2^20305947 is an apocalyptic number.

20305947 is a deficient number, since it is larger than the sum of its proper divisors (7429173).

20305947 is a wasteful number, since it uses less digits than its factorization.

20305947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165133.

The product of its (nonzero) digits is 7560, while the sum is 30.

The square root of 20305947 is about 4506.2120456099. The cubic root of 20305947 is about 272.8188764913.

The spelling of 20305947 in words is "twenty million, three hundred five thousand, nine hundred forty-seven".