216800138 has 4 divisors (see below), whose sum is σ = 325200210. Its totient is φ = 108400068.

The previous prime is 216800137. The next prime is 216800149. The reversal of 216800138 is 831008612.

216800138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in only one way, i.e., 148522969 + 68277169 = 12187^2 + 8263^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 216800138.

It is not an unprimeable number, because it can be changed into a prime (216800137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54200033 + ... + 54200036.

Almost surely, 2^216800138 is an apocalyptic number.

216800138 is a deficient number, since it is larger than the sum of its proper divisors (108400072).

216800138 is a wasteful number, since it uses less digits than its factorization.

216800138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108400071.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 216800138 is about 14724.1345416293. The cubic root of 216800138 is about 600.7399555863.

The spelling of 216800138 in words is "two hundred sixteen million, eight hundred thousand, one hundred thirty-eight".