6816645 has 48 divisors (see below), whose sum is σ = 13208832. Its totient is φ = 3223680.

The previous prime is 6816631. The next prime is 6816659. The reversal of 6816645 is 5466186.

6816645 is a `hidden beast` number, since 6 + 8 + 1 + 6 + 645 = 666.

It is an interprime number because it is at equal distance from previous prime (6816631) and next prime (6816659).

It is not a de Polignac number, because 6816645 - 2⁴ = 6816629 is a prime.

6816645 is a lucky number.

It is a plaindrome in base 12.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23119 + ... + 23411.

It is an arithmetic number, because the mean of its divisors is an integer number (275184).

Almost surely, 2^6816645 is an apocalyptic number.

It is an amenable number.

6816645 is a deficient number, since it is larger than the sum of its proper divisors (6392187).

6816645 is a wasteful number, since it uses less digits than its factorization.

6816645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362 (or 359 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 6816645 is about 2610.8705444736. The cubic root of 6816645 is about 189.6081026554.

The spelling of 6816645 in words is "six million, eight hundred sixteen thousand, six hundred forty-five".