7266821 has 4 divisors (see below), whose sum is σ = 7273644. Its totient is φ = 7260000.

The previous prime is 7266817. The next prime is 7266823. The reversal of 7266821 is 1286627.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1286627 = 269 ⋅4783.

It can be written as a sum of positive squares in 2 ways, for example, as 6964321 + 302500 = 2639^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 7266821 - 2² = 7266817 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 (7266823) 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, 1430 + ... + 4071.

It is an arithmetic number, because the mean of its divisors is an integer number (1818411).

Almost surely, 2^7266821 is an apocalyptic number.

It is an amenable number.

7266821 is a deficient number, since it is larger than the sum of its proper divisors (6823).

7266821 is a wasteful number, since it uses less digits than its factorization.

7266821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6822.

The product of its digits is 8064, while the sum is 32.

The square root of 7266821 is about 2695.7041751646. The cubic root of 7266821 is about 193.6933992141.

The spelling of 7266821 in words is "seven million, two hundred sixty-six thousand, eight hundred twenty-one".