2121649173 has 64 divisors (see below), whose sum is σ = 3650027520. Its totient is φ = 1193040576.

The previous prime is 2121649169. The next prime is 2121649183. The reversal of 2121649173 is 3719461212.

2121649173 is a `hidden beast` number, since 2 + 1 + 2 + 1 + 649 + 1 + 7 + 3 = 666.

It is not a de Polignac number, because 2121649173 - 2² = 2121649169 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121649183) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3768190 + ... + 3768752.

It is an arithmetic number, because the mean of its divisors is an integer number (57031680).

Almost surely, 2^2121649173 is an apocalyptic number.

It is an amenable number.

2121649173 is a deficient number, since it is larger than the sum of its proper divisors (1528378347).

2121649173 is a wasteful number, since it uses less digits than its factorization.

2121649173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 863 (or 857 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 2121649173 is about 46061.3631257261. The cubic root of 2121649173 is about 1284.9646814115.

The spelling of 2121649173 in words is "two billion, one hundred twenty-one million, six hundred forty-nine thousand, one hundred seventy-three".