2121987447 has 48 divisors (see below), whose sum is σ = 3330445248. Its totient is φ = 1296921600.

The previous prime is 2121987421. The next prime is 2121987457. The reversal of 2121987447 is 7447891212.

2121987447 is a `hidden beast` number, since 2 + 12 + 198 + 7 + 447 = 666.

It is not a de Polignac number, because 2121987447 - 2¹⁰ = 2121986423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121987457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1223593 + ... + 1225325.

It is an arithmetic number, because the mean of its divisors is an integer number (69384276).

Almost surely, 2^2121987447 is an apocalyptic number.

2121987447 is a deficient number, since it is larger than the sum of its proper divisors (1208457801).

2121987447 is a wasteful number, since it uses less digits than its factorization.

2121987447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1960 (or 1957 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 2121987447 is about 46065.0349723084. The cubic root of 2121987447 is about 1285.0329690199.

The spelling of 2121987447 in words is "two billion, one hundred twenty-one million, nine hundred eighty-seven thousand, four hundred forty-seven".