6406661 has 8 divisors (see below), whose sum is σ = 6612000. Its totient is φ = 6203088.

The previous prime is 6406657. The next prime is 6406679. The reversal of 6406661 is 1666046.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6406661 - 2² = 6406657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6406601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12590 + ... + 13088.

It is an arithmetic number, because the mean of its divisors is an integer number (826500).

Almost surely, 2^6406661 is an apocalyptic number.

It is an amenable number.

6406661 is a deficient number, since it is larger than the sum of its proper divisors (205339).

6406661 is a wasteful number, since it uses less digits than its factorization.

6406661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 6406661 is about 2531.1382814852. The cubic root of 6406661 is about 185.7279427263.

The spelling of 6406661 in words is "six million, four hundred six thousand, six hundred sixty-one".