7821641 has 8 divisors (see below), whose sum is σ = 8122368. Its totient is φ = 7524000.

The previous prime is 7821637. The next prime is 7821643. The reversal of 7821641 is 1461287.

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 7821641 - 2² = 7821637 is a prime.

It is a super-3 number, since 3×7821641³ (a number of 22 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7821643) 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, 5261 + ... + 6581.

It is an arithmetic number, because the mean of its divisors is an integer number (1015296).

Almost surely, 2^7821641 is an apocalyptic number.

It is an amenable number.

7821641 is a deficient number, since it is larger than the sum of its proper divisors (300727).

7821641 is a wasteful number, since it uses less digits than its factorization.

7821641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1543.

The product of its digits is 2688, while the sum is 29.

The square root of 7821641 is about 2796.7196856317. The cubic root of 7821641 is about 198.5024903088.

The spelling of 7821641 in words is "seven million, eight hundred twenty-one thousand, six hundred forty-one".