7645821 has 16 divisors (see below), whose sum is σ = 11007360. Its totient is φ = 4706240.

The previous prime is 7645817. The next prime is 7645837. The reversal of 7645821 is 1285467.

It is a cyclic number.

It is not a de Polignac number, because 7645821 - 2² = 7645817 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7645861) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91 + ... + 3911.

It is an arithmetic number, because the mean of its divisors is an integer number (687960).

Almost surely, 2^7645821 is an apocalyptic number.

It is an amenable number.

7645821 is a deficient number, since it is larger than the sum of its proper divisors (3361539).

7645821 is a wasteful number, since it uses less digits than its factorization.

7645821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3876.

The product of its digits is 13440, while the sum is 33.

The square root of 7645821 is about 2765.1077736681. The cubic root of 7645821 is about 197.0038478295.

The spelling of 7645821 in words is "seven million, six hundred forty-five thousand, eight hundred twenty-one".