18171961 has 8 divisors (see below), whose sum is σ = 19443200. Its totient is φ = 16932240.

The previous prime is 18171949. The next prime is 18171971. The reversal of 18171961 is 16917181.

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 18171961 - 2¹¹ = 18169913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18171971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6681 + ... + 8998.

It is an arithmetic number, because the mean of its divisors is an integer number (2430400).

Almost surely, 2^18171961 is an apocalyptic number.

It is an amenable number.

18171961 is a deficient number, since it is larger than the sum of its proper divisors (1271239).

18171961 is a wasteful number, since it uses less digits than its factorization.

18171961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15759.

The product of its digits is 3024, while the sum is 34.

The square root of 18171961 is about 4262.8583133855. The cubic root of 18171961 is about 262.9060611849.

The spelling of 18171961 in words is "eighteen million, one hundred seventy-one thousand, nine hundred sixty-one".