6645556 has 12 divisors (see below), whose sum is σ = 11739168. Its totient is φ = 3291512.

The previous prime is 6645547. The next prime is 6645557. The reversal of 6645556 is 6555466.

It is a super-3 number, since 3×6645556³ (a number of 21 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6645557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7336 + ... + 8191.

It is an arithmetic number, because the mean of its divisors is an integer number (978264).

Almost surely, 2^6645556 is an apocalyptic number.

It is an amenable number.

6645556 is a deficient number, since it is larger than the sum of its proper divisors (5093612).

6645556 is a wasteful number, since it uses less digits than its factorization.

6645556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15638 (or 15636 counting only the distinct ones).

The product of its digits is 108000, while the sum is 37.

The square root of 6645556 is about 2577.8975930009. The cubic root of 6645556 is about 188.0083367361.

The spelling of 6645556 in words is "six million, six hundred forty-five thousand, five hundred fifty-six".