18120406 has 4 divisors (see below), whose sum is σ = 27180612. Its totient is φ = 9060202.

The previous prime is 18120391. The next prime is 18120413. The reversal of 18120406 is 60402181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60402181 = 7 ⋅8628883.

It is a super-2 number, since 2×18120406² = 656698227209672, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4530100 + ... + 4530103.

It is an arithmetic number, because the mean of its divisors is an integer number (6795153).

Almost surely, 2^18120406 is an apocalyptic number.

18120406 is a deficient number, since it is larger than the sum of its proper divisors (9060206).

18120406 is an equidigital number, since it uses as much as digits as its factorization.

18120406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9060205.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 18120406 is about 4256.8070193515. The cubic root of 18120406 is about 262.6571986618.

Adding to 18120406 its reverse (60402181), we get a palindrome (78522587).

The spelling of 18120406 in words is "eighteen million, one hundred twenty thousand, four hundred six".