31356666 has 48 divisors (see below), whose sum is σ = 76608000. Its totient is φ = 9500040.

The previous prime is 31356643. The next prime is 31356667. The reversal of 31356666 is 66665313.

It is a happy number.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31356666.

It is not an unprimeable number, because it can be changed into a prime (31356667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4135 + ... + 8933.

It is an arithmetic number, because the mean of its divisors is an integer number (1596000).

Almost surely, 2^31356666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31356666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38304000).

31356666 is an abundant number, since it is smaller than the sum of its proper divisors (45251334).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31356666 is a wasteful number, since it uses less digits than its factorization.

31356666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4832 (or 4815 counting only the distinct ones).

The product of its digits is 58320, while the sum is 36.

The square root of 31356666 is about 5599.7023135163. The cubic root of 31356666 is about 315.3382307995.

It can be divided in two parts, 3135 and 6666, that added together give a square (9801 = 99²).

The spelling of 31356666 in words is "thirty-one million, three hundred fifty-six thousand, six hundred sixty-six".