20518238 has 16 divisors (see below), whose sum is σ = 33521040. Its totient is φ = 9362496.

The previous prime is 20518229. The next prime is 20518241. The reversal of 20518238 is 83281502.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20518238.

It is a congruent number.

It is an unprimeable number.

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, 2120 + ... + 6747.

It is an arithmetic number, because the mean of its divisors is an integer number (2095065).

Almost surely, 2^20518238 is an apocalyptic number.

20518238 is a deficient number, since it is larger than the sum of its proper divisors (13002802).

20518238 is a wasteful number, since it uses less digits than its factorization.

20518238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8971.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 20518238 is about 4529.7061714862. The cubic root of 20518238 is about 273.7663218030.

The spelling of 20518238 in words is "twenty million, five hundred eighteen thousand, two hundred thirty-eight".