18172047211 has 4 divisors (see below), whose sum is σ = 18173684232. Its totient is φ = 18170410192.

The previous prime is 18172047209. The next prime is 18172047239. The reversal of 18172047211 is 11274027181.

It is a happy number.

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 18172047211 - 2¹ = 18172047209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18172047611) 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, 801745 + ... + 824098.

It is an arithmetic number, because the mean of its divisors is an integer number (4543421058).

Almost surely, 2^18172047211 is an apocalyptic number.

18172047211 is a deficient number, since it is larger than the sum of its proper divisors (1637021).

18172047211 is a wasteful number, since it uses less digits than its factorization.

18172047211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1637020.

The product of its (nonzero) digits is 6272, while the sum is 34.

The spelling of 18172047211 in words is "eighteen billion, one hundred seventy-two million, forty-seven thousand, two hundred eleven".