6661556 has 24 divisors (see below), whose sum is σ = 12852000. Its totient is φ = 2996000.

The previous prime is 6661553. The next prime is 6661583. The reversal of 6661556 is 6551666.

It is a super-2 number, since 2×6661556² = 88752656682272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661553) 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, 3695 + ... + 5193.

It is an arithmetic number, because the mean of its divisors is an integer number (535500).

Almost surely, 2^6661556 is an apocalyptic number.

It is an amenable number.

6661556 is a deficient number, since it is larger than the sum of its proper divisors (6190444).

6661556 is a wasteful number, since it uses less digits than its factorization.

6661556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615 (or 1613 counting only the distinct ones).

The product of its digits is 32400, while the sum is 35.

The square root of 6661556 is about 2580.9990313830. Note that the first 3 decimals coincide. The cubic root of 6661556 is about 188.1591002669.

It can be divided in two parts, 666 and 1556, that added together give a palindrome (2222).

The spelling of 6661556 in words is "six million, six hundred sixty-one thousand, five hundred fifty-six".