2121015555 has 12 divisors (see below), whose sum is σ = 3676427040. Its totient is φ = 1131208272.

The previous prime is 2121015553. The next prime is 2121015563. The reversal of 2121015555 is 5555101212.

2121015555 is a `hidden beast` number, since 2 + 1 + 2 + 101 + 5 + 555 = 666.

It is not a de Polignac number, because 2121015555 - 2¹ = 2121015553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2121015553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23566795 + ... + 23566884.

It is an arithmetic number, because the mean of its divisors is an integer number (306368920).

Almost surely, 2^2121015555 is an apocalyptic number.

2121015555 is a deficient number, since it is larger than the sum of its proper divisors (1555411485).

2121015555 is a wasteful number, since it uses less digits than its factorization.

2121015555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47133690 (or 47133687 counting only the distinct ones).

The product of its (nonzero) digits is 2500, while the sum is 27.

The square root of 2121015555 is about 46054.4846350494. The cubic root of 2121015555 is about 1284.8367529703.

Adding to 2121015555 its reverse (5555101212), we get a palindrome (7676116767).

The spelling of 2121015555 in words is "two billion, one hundred twenty-one million, fifteen thousand, five hundred fifty-five".