20118971 has 4 divisors (see below), whose sum is σ = 20131944. Its totient is φ = 20106000.

The previous prime is 20118947. The next prime is 20118979. The reversal of 20118971 is 17981102.

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 20118971 - 2¹⁰ = 20117947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20118979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3785 + ... + 7386.

It is an arithmetic number, because the mean of its divisors is an integer number (5032986).

Almost surely, 2^20118971 is an apocalyptic number.

20118971 is a deficient number, since it is larger than the sum of its proper divisors (12973).

20118971 is a wasteful number, since it uses less digits than its factorization.

20118971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12972.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 20118971 is about 4485.4175948288. The cubic root of 20118971 is about 271.9789262436.

The spelling of 20118971 in words is "twenty million, one hundred eighteen thousand, nine hundred seventy-one".