7281921 has 16 divisors (see below), whose sum is σ = 10461440. Its totient is φ = 4490640.

The previous prime is 7281919. The next prime is 7281941. The reversal of 7281921 is 1291827.

It is not a de Polignac number, because 7281921 - 2¹ = 7281919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7281941) 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 15 ways as a sum of consecutive naturals, for example, 966 + ... + 3936.

It is an arithmetic number, because the mean of its divisors is an integer number (653840).

Almost surely, 2^7281921 is an apocalyptic number.

It is an amenable number.

7281921 is a deficient number, since it is larger than the sum of its proper divisors (3179519).

7281921 is a wasteful number, since it uses less digits than its factorization.

7281921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3036.

The product of its digits is 2016, while the sum is 30.

The square root of 7281921 is about 2698.5034741501. The cubic root of 7281921 is about 193.8274673224.

The spelling of 7281921 in words is "seven million, two hundred eighty-one thousand, nine hundred twenty-one".