31666636 has 6 divisors (see below), whose sum is σ = 55416620. Its totient is φ = 15833316.

The previous prime is 31666633. The next prime is 31666643. The reversal of 31666636 is 63666613.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 31666595 and 31666604.

It is not an unprimeable number, because it can be changed into a prime (31666633) 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 as a sum of consecutive naturals, namely, 3958326 + ... + 3958333.

Almost surely, 2^31666636 is an apocalyptic number.

It is an amenable number.

31666636 is a deficient number, since it is larger than the sum of its proper divisors (23749984).

31666636 is a wasteful number, since it uses less digits than its factorization.

31666636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7916663 (or 7916661 counting only the distinct ones).

The product of its digits is 69984, while the sum is 37.

The square root of 31666636 is about 5627.3116139059. The cubic root of 31666636 is about 316.3738964732.

The spelling of 31666636 in words is "thirty-one million, six hundred sixty-six thousand, six hundred thirty-six".