18156442 has 8 divisors (see below), whose sum is σ = 28836756. Its totient is φ = 8544192.

The previous prime is 18156433. The next prime is 18156461. The reversal of 18156442 is 24465181.

It can be written as a sum of positive squares in 2 ways, for example, as 16966161 + 1190281 = 4119^2 + 1091^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266973 + ... + 267040.

Almost surely, 2^18156442 is an apocalyptic number.

18156442 is a deficient number, since it is larger than the sum of its proper divisors (10680314).

18156442 is a wasteful number, since it uses less digits than its factorization.

18156442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 534032.

The product of its digits is 7680, while the sum is 31.

The square root of 18156442 is about 4261.0376670478. The cubic root of 18156442 is about 262.8311985769.

The spelling of 18156442 in words is "eighteen million, one hundred fifty-six thousand, four hundred forty-two".