2121154115 has 4 divisors (see below), whose sum is σ = 2545384944. Its totient is φ = 1696923288.

The previous prime is 2121154111. The next prime is 2121154151. The reversal of 2121154115 is 5114511212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 2121154115 - 2² = 2121154111 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2121154111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 212115407 + ... + 212115416.

It is an arithmetic number, because the mean of its divisors is an integer number (636346236).

Almost surely, 2^2121154115 is an apocalyptic number.

2121154115 is a deficient number, since it is larger than the sum of its proper divisors (424230829).

2121154115 is an equidigital number, since it uses as much as digits as its factorization.

2121154115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424230828.

The product of its digits is 400, while the sum is 23.

The square root of 2121154115 is about 46055.9889156665. The cubic root of 2121154115 is about 1284.8647306221.

Adding to 2121154115 its reverse (5114511212), we get a palindrome (7235665327).

The spelling of 2121154115 in words is "two billion, one hundred twenty-one million, one hundred fifty-four thousand, one hundred fifteen".