218204101 has 4 divisors (see below), whose sum is σ = 218370604. Its totient is φ = 218037600.

The previous prime is 218204099. The next prime is 218204117. The reversal of 218204101 is 101402812.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 207648100 + 10556001 = 14410^2 + 3249^2 .

It is a cyclic number.

It is not a de Polignac number, because 218204101 - 2¹ = 218204099 is a prime.

It is a super-2 number, since 2×218204101² = 95226059386436402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218204201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81270 + ... + 83911.

It is an arithmetic number, because the mean of its divisors is an integer number (54592651).

Almost surely, 2^218204101 is an apocalyptic number.

It is an amenable number.

218204101 is a deficient number, since it is larger than the sum of its proper divisors (166503).

218204101 is a wasteful number, since it uses less digits than its factorization.

218204101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166502.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 218204101 is about 14771.7331752235. The cubic root of 218204101 is about 602.0339316717.

Adding to 218204101 its reverse (101402812), we get a palindrome (319606913).

It can be divided in two parts, 21820 and 4101, that added together give a square (25921 = 161²).

The spelling of 218204101 in words is "two hundred eighteen million, two hundred four thousand, one hundred one".