1006645 has 4 divisors (see below), whose sum is σ = 1207980. Its totient is φ = 805312.

The previous prime is 1006637. The next prime is 1006651. The reversal of 1006645 is 5466001.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5466001 = 229 ⋅23869.

It can be written as a sum of positive squares in 2 ways, for example, as 758641 + 248004 = 871^2 + 498^2 .

It is a cyclic number.

It is not a de Polignac number, because 1006645 - 2³ = 1006637 is a prime.

It is a Smith number, since the sum of its digits (22) 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 an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 100660 + ... + 100669.

It is an arithmetic number, because the mean of its divisors is an integer number (301995).

2^1006645 is an apocalyptic number.

It is an amenable number.

1006645 is a deficient number, since it is larger than the sum of its proper divisors (201335).

1006645 is an equidigital number, since it uses as much as digits as its factorization.

1006645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201334.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 1006645 is about 1003.3169987596. The cubic root of 1006645 is about 100.2210111807.

The spelling of 1006645 in words is "one million, six thousand, six hundred forty-five".