18705971 has 4 divisors (see below), whose sum is σ = 18814272. Its totient is φ = 18597672.

The previous prime is 18705949. The next prime is 18705977. The reversal of 18705971 is 17950781.

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-18705971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18705977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53891 + ... + 54236.

It is an arithmetic number, because the mean of its divisors is an integer number (4703568).

Almost surely, 2^18705971 is an apocalyptic number.

18705971 is a deficient number, since it is larger than the sum of its proper divisors (108301).

18705971 is a wasteful number, since it uses less digits than its factorization.

18705971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108300.

The product of its (nonzero) digits is 17640, while the sum is 38.

The square root of 18705971 is about 4325.0399998150. The cubic root of 18705971 is about 265.4565335642.

The spelling of 18705971 in words is "eighteen million, seven hundred five thousand, nine hundred seventy-one".