2663921 has 4 divisors (see below), whose sum is σ = 2868852. Its totient is φ = 2458992.

The previous prime is 2663897. The next prime is 2663953. The reversal of 2663921 is 1293662.

2663921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1293662 = 2 ⋅646831.

It can be written as a sum of positive squares in 2 ways, for example, as 703921 + 1960000 = 839^2 + 1400^2 .

It is a cyclic number.

It is not a de Polignac number, because 2663921 - 2¹⁴ = 2647537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2662921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102446 + ... + 102471.

It is an arithmetic number, because the mean of its divisors is an integer number (717213).

2^2663921 is an apocalyptic number.

It is an amenable number.

2663921 is a deficient number, since it is larger than the sum of its proper divisors (204931).

2663921 is a wasteful number, since it uses less digits than its factorization.

2663921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204930.

The product of its digits is 3888, while the sum is 29.

The square root of 2663921 is about 1632.1522600542. The cubic root of 2663921 is about 138.6246450528.

The spelling of 2663921 in words is "two million, six hundred sixty-three thousand, nine hundred twenty-one".