18017421 has 8 divisors (see below), whose sum is σ = 24059520. Its totient is φ = 11993472.

The previous prime is 18017413. The next prime is 18017429. The reversal of 18017421 is 12471081.

It is an interprime number because it is at equal distance from previous prime (18017413) and next prime (18017429).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18017421 - 2³ = 18017413 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18017391 and 18017400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18017429) 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, 2020 + ... + 6333.

It is an arithmetic number, because the mean of its divisors is an integer number (3007440).

Almost surely, 2^18017421 is an apocalyptic number.

It is an amenable number.

18017421 is a deficient number, since it is larger than the sum of its proper divisors (6042099).

18017421 is an equidigital number, since it uses as much as digits as its factorization.

18017421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9075.

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 18017421 is about 4244.6932751378. The cubic root of 18017421 is about 262.1586601887.

The spelling of 18017421 in words is "eighteen million, seventeen thousand, four hundred twenty-one".