2118215205 has 56 divisors (see below), whose sum is σ = 3821084280. Its totient is φ = 1126742400.

The previous prime is 2118215201. The next prime is 2118215221. The reversal of 2118215205 is 5025128112.

It is a happy number.

2118215205 is a `hidden beast` number, since 2 + 118 + 21 + 520 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 602358849 + 1515856356 = 24543^2 + 38934^2 .

It is not a de Polignac number, because 2118215205 - 2² = 2118215201 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2118215201) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 2554731 + ... + 2555559.

Almost surely, 2^2118215205 is an apocalyptic number.

It is an amenable number.

2118215205 is a deficient number, since it is larger than the sum of its proper divisors (1702869075).

2118215205 is an frugal number, since it uses more digits than its factorization.

2118215205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1553 (or 1538 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The square root of 2118215205 is about 46024.0720167175. The cubic root of 2118215205 is about 1284.2710526989.

The spelling of 2118215205 in words is "two billion, one hundred eighteen million, two hundred fifteen thousand, two hundred five".