18202138 has 16 divisors (see below), whose sum is σ = 29111400. Its totient is φ = 8505856.

The previous prime is 18202123. The next prime is 18202139. The reversal of 18202138 is 83120281.

It can be written as a sum of positive squares in 4 ways, for example, as 13126129 + 5076009 = 3623^2 + 2253^2 .

It is not an unprimeable number, because it can be changed into a prime (18202139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3270 + ... + 6862.

Almost surely, 2^18202138 is an apocalyptic number.

18202138 is a deficient number, since it is larger than the sum of its proper divisors (10909262).

18202138 is a wasteful number, since it uses less digits than its factorization.

18202138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3761.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 18202138 is about 4266.3963716467. The cubic root of 18202138 is about 263.0515110639.

The spelling of 18202138 in words is "eighteen million, two hundred two thousand, one hundred thirty-eight".