31661666 has 16 divisors (see below), whose sum is σ = 48185280. Its totient is φ = 15601680.

The previous prime is 31661611. The next prime is 31661681. The reversal of 31661666 is 66616613.

It is a super-2 number, since 2×31661666² = 2004922187791112, which contains 22 as substring.

It is an unprimeable number.

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, 67565 + ... + 68031.

It is an arithmetic number, because the mean of its divisors is an integer number (3011580).

Almost surely, 2^31661666 is an apocalyptic number.

31661666 is a deficient number, since it is larger than the sum of its proper divisors (16523614).

31661666 is a wasteful number, since it uses less digits than its factorization.

31661666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 889.

The product of its digits is 23328, while the sum is 35.

The square root of 31661666 is about 5626.8700002755. The cubic root of 31661666 is about 316.3573442410.

The spelling of 31661666 in words is "thirty-one million, six hundred sixty-one thousand, six hundred sixty-six".