18077981 has 8 divisors (see below), whose sum is σ = 18416160. Its totient is φ = 17742832.

The previous prime is 18077963. The next prime is 18077989. The reversal of 18077981 is 18977081.

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 18077981 - 2¹⁴ = 18061597 is a prime.

It is a super-2 number, since 2×18077981² = 653626794072722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18077989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13730 + ... + 14988.

It is an arithmetic number, because the mean of its divisors is an integer number (2302020).

Almost surely, 2^18077981 is an apocalyptic number.

It is an amenable number.

18077981 is a deficient number, since it is larger than the sum of its proper divisors (338179).

18077981 is a wasteful number, since it uses less digits than its factorization.

18077981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1515.

The product of its (nonzero) digits is 28224, while the sum is 41.

The square root of 18077981 is about 4251.8209040363. The cubic root of 18077981 is about 262.4520535256.

The spelling of 18077981 in words is "eighteen million, seventy-seven thousand, nine hundred eighty-one".