7921885 has 8 divisors (see below), whose sum is σ = 9763416. Its totient is φ = 6166080.

The previous prime is 7921873. The next prime is 7921889. The reversal of 7921885 is 5881297.

It can be written as a sum of positive squares in 4 ways, for example, as 534361 + 7387524 = 731^2 + 2718^2 .

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

It is not a de Polignac number, because 7921885 - 2⁷ = 7921757 is a prime.

It is an Ulam number.

It is a Duffinian number.

7921885 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7921889) 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, 21226 + ... + 21595.

It is an arithmetic number, because the mean of its divisors is an integer number (1220427).

Almost surely, 2^7921885 is an apocalyptic number.

It is an amenable number.

7921885 is a deficient number, since it is larger than the sum of its proper divisors (1841531).

7921885 is a wasteful number, since it uses less digits than its factorization.

7921885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42863.

The product of its digits is 40320, while the sum is 40.

The square root of 7921885 is about 2814.5843387612. The cubic root of 7921885 is about 199.3469113642.

The spelling of 7921885 in words is "seven million, nine hundred twenty-one thousand, eight hundred eighty-five".