7993821 has 16 divisors (see below), whose sum is σ = 12029760. Its totient is φ = 4677120.

The previous prime is 7993801. The next prime is 7993823. The reversal of 7993821 is 1283997.

It is not a de Polignac number, because 7993821 - 2⁷ = 7993693 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 7993821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7993823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3220 + ... + 5133.

It is an arithmetic number, because the mean of its divisors is an integer number (751860).

Almost surely, 2^7993821 is an apocalyptic number.

It is an amenable number.

7993821 is a deficient number, since it is larger than the sum of its proper divisors (4035939).

7993821 is a wasteful number, since it uses less digits than its factorization.

7993821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8396.

The product of its digits is 27216, while the sum is 39.

The square root of 7993821 is about 2827.3346105475. The cubic root of 7993821 is about 199.9484950707.

The spelling of 7993821 in words is "seven million, nine hundred ninety-three thousand, eight hundred twenty-one".