3666981 has 8 divisors (see below), whose sum is σ = 5146720. Its totient is φ = 2315952.

The previous prime is 3666979. The next prime is 3666991. The reversal of 3666981 is 1896663.

It is a happy number.

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

It is not a de Polignac number, because 3666981 - 2¹ = 3666979 is a prime.

It is a super-2 number, since 2×3666981² = 26893499308722, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3666961) 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 7 ways as a sum of consecutive naturals, for example, 32110 + ... + 32223.

It is an arithmetic number, because the mean of its divisors is an integer number (643340).

Almost surely, 2^3666981 is an apocalyptic number.

It is an amenable number.

3666981 is a deficient number, since it is larger than the sum of its proper divisors (1479739).

3666981 is a wasteful number, since it uses less digits than its factorization.

3666981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64355.

The product of its digits is 46656, while the sum is 39.

The square root of 3666981 is about 1914.9362913685. The cubic root of 3666981 is about 154.2065732906.

The spelling of 3666981 in words is "three million, six hundred sixty-six thousand, nine hundred eighty-one".