7904821 has 8 divisors (see below), whose sum is σ = 8043840. Its totient is φ = 7767168.

The previous prime is 7904773. The next prime is 7904843. The reversal of 7904821 is 1284097.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 7904821 - 2¹⁷ = 7773749 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 (7904321) 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 7 ways as a sum of consecutive naturals, for example, 21840 + ... + 22198.

It is an arithmetic number, because the mean of its divisors is an integer number (1005480).

Almost surely, 2^7904821 is an apocalyptic number.

It is an amenable number.

7904821 is a deficient number, since it is larger than the sum of its proper divisors (139019).

7904821 is a wasteful number, since it uses less digits than its factorization.

7904821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 683.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 7904821 is about 2811.5513511227. The cubic root of 7904821 is about 199.2036752089.

The spelling of 7904821 in words is "seven million, nine hundred four thousand, eight hundred twenty-one".