18145555 has 4 divisors (see below), whose sum is σ = 21774672. Its totient is φ = 14516440.

The previous prime is 18145529. The next prime is 18145637. The reversal of 18145555 is 55554181.

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

It is a de Polignac number, because none of the positive numbers 2^k-18145555 is a prime.

It is a super-2 number, since 2×18145555² = 658522332516050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18145555.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1814551 + ... + 1814560.

It is an arithmetic number, because the mean of its divisors is an integer number (5443668).

Almost surely, 2^18145555 is an apocalyptic number.

18145555 is a deficient number, since it is larger than the sum of its proper divisors (3629117).

18145555 is an equidigital number, since it uses as much as digits as its factorization.

18145555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3629116.

The product of its digits is 20000, while the sum is 34.

The square root of 18145555 is about 4259.7599697636. The cubic root of 18145555 is about 262.7786549604.

The spelling of 18145555 in words is "eighteen million, one hundred forty-five thousand, five hundred fifty-five".