6621345 has 20 divisors (see below), whose sum is σ = 11870100. Its totient is φ = 3531168.

The previous prime is 6621341. The next prime is 6621353. The reversal of 6621345 is 5431266.

6621345 is a `hidden beast` number, since 6 + 621 + 34 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1679616 + 4941729 = 1296^2 + 2223^2 .

It is not a de Polignac number, because 6621345 - 2² = 6621341 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (6621341) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7770 + ... + 8579.

It is an arithmetic number, because the mean of its divisors is an integer number (593505).

Almost surely, 2^6621345 is an apocalyptic number.

It is an amenable number.

6621345 is a deficient number, since it is larger than the sum of its proper divisors (5248755).

6621345 is a wasteful number, since it uses less digits than its factorization.

6621345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16366 (or 16357 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 6621345 is about 2573.1974273266. The cubic root of 6621345 is about 187.7797424280.

The spelling of 6621345 in words is "six million, six hundred twenty-one thousand, three hundred forty-five".