18102421 has 8 divisors (see below), whose sum is σ = 19368800. Its totient is φ = 16867440.

The previous prime is 18102397. The next prime is 18102437. The reversal of 18102421 is 12420181.

It is a happy number.

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

It is not a de Polignac number, because 18102421 - 2⁵ = 18102389 is a prime.

It is a super-2 number, since 2×18102421² = 655395292122482, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18102451) 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, 6651 + ... + 8968.

It is an arithmetic number, because the mean of its divisors is an integer number (2421100).

Almost surely, 2^18102421 is an apocalyptic number.

It is an amenable number.

18102421 is a deficient number, since it is larger than the sum of its proper divisors (1266379).

18102421 is a wasteful number, since it uses less digits than its factorization.

18102421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15699.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 18102421 is about 4254.6939960472. The cubic root of 18102421 is about 262.5702717382.

The spelling of 18102421 in words is "eighteen million, one hundred two thousand, four hundred twenty-one".