18078461 has 4 divisors (see below), whose sum is σ = 18178524. Its totient is φ = 17978400.

The previous prime is 18078449. The next prime is 18078491. The reversal of 18078461 is 16487081.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9703225 + 8375236 = 3115^2 + 2894^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18078461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18078491) 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, 49760 + ... + 50121.

It is an arithmetic number, because the mean of its divisors is an integer number (4544631).

Almost surely, 2^18078461 is an apocalyptic number.

It is an amenable number.

18078461 is a deficient number, since it is larger than the sum of its proper divisors (100063).

18078461 is an equidigital number, since it uses as much as digits as its factorization.

18078461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100062.

The product of its (nonzero) digits is 10752, while the sum is 35.

The square root of 18078461 is about 4251.8773500655. The cubic root of 18078461 is about 262.4543763490.

The spelling of 18078461 in words is "eighteen million, seventy-eight thousand, four hundred sixty-one".