18740971 has 4 divisors (see below), whose sum is σ = 18754744. Its totient is φ = 18727200.

The previous prime is 18740941. The next prime is 18740993. The reversal of 18740971 is 17904781.

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

It is a 5-Lehmer number, since φ(18740971) divides (18740971-1)⁵.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18740971 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18740971.

It is not an unprimeable number, because it can be changed into a prime (18740941) 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, 4590 + ... + 7651.

It is an arithmetic number, because the mean of its divisors is an integer number (4688686).

It is a Poulet number, since it divides 2^18740970-1.

Almost surely, 2^18740971 is an apocalyptic number.

18740971 is a deficient number, since it is larger than the sum of its proper divisors (13773).

18740971 is a wasteful number, since it uses less digits than its factorization.

18740971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13772.

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 18740971 is about 4329.0843142632. The cubic root of 18740971 is about 265.6219921413.

The spelling of 18740971 in words is "eighteen million, seven hundred forty thousand, nine hundred seventy-one".