6666406 has 4 divisors (see below), whose sum is σ = 9999612. Its totient is φ = 3333202.

The previous prime is 6666391. The next prime is 6666437. The reversal of 6666406 is 6046666.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1666600 + ... + 1666603.

It is an arithmetic number, because the mean of its divisors is an integer number (2499903).

Almost surely, 2^6666406 is an apocalyptic number.

6666406 is a deficient number, since it is larger than the sum of its proper divisors (3333206).

6666406 is a wasteful number, since it uses less digits than its factorization.

6666406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3333205.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 6666406 is about 2581.9384190952. The cubic root of 6666406 is about 188.2047527770.

The spelling of 6666406 in words is "six million, six hundred sixty-six thousand, four hundred six".