6667561 has 4 divisors (see below), whose sum is σ = 6809472. Its totient is φ = 6525652.

The previous prime is 6667541. The next prime is 6667589. The reversal of 6667561 is 1657666.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1657666 = 2 ⋅828833.

It is a cyclic number.

It is not a de Polignac number, because 6667561 - 2⁹ = 6667049 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6667561.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6667541) 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 3 ways as a sum of consecutive naturals, for example, 70885 + ... + 70978.

It is an arithmetic number, because the mean of its divisors is an integer number (1702368).

Almost surely, 2^6667561 is an apocalyptic number.

It is an amenable number.

6667561 is a deficient number, since it is larger than the sum of its proper divisors (141911).

6667561 is a wasteful number, since it uses less digits than its factorization.

6667561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141910.

The product of its digits is 45360, while the sum is 37.

The square root of 6667561 is about 2582.1620785690. The cubic root of 6667561 is about 188.2156213988.

The spelling of 6667561 in words is "six million, six hundred sixty-seven thousand, five hundred sixty-one".