2121647 has 4 divisors (see below), whose sum is σ = 2314536. Its totient is φ = 1928760.

The previous prime is 2121631. The next prime is 2121653. The reversal of 2121647 is 7461212.

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 2121647 - 2⁴ = 2121631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96428 + ... + 96449.

It is an arithmetic number, because the mean of its divisors is an integer number (578634).

2^2121647 is an apocalyptic number.

2121647 is a deficient number, since it is larger than the sum of its proper divisors (192889).

2121647 is a wasteful number, since it uses less digits than its factorization.

2121647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192888.

The product of its digits is 672, while the sum is 23.

The square root of 2121647 is about 1456.5874501725. The cubic root of 2121647 is about 128.4964242723.

Adding to 2121647 its reverse (7461212), we get a palindrome (9582859).

The spelling of 2121647 in words is "two million, one hundred twenty-one thousand, six hundred forty-seven".