31728133 has 2 divisors, whose sum is σ = 31728134. Its totient is φ = 31728132.

The previous prime is 31728131. The next prime is 31728181. The reversal of 31728133 is 33182713.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19210689 + 12517444 = 4383^2 + 3538^2 .

It is a cyclic number.

It is not a de Polignac number, because 31728133 - 2¹ = 31728131 is a prime.

Together with 31728131, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31728131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15864066 + 15864067.

It is an arithmetic number, because the mean of its divisors is an integer number (15864067).

Almost surely, 2^31728133 is an apocalyptic number.

It is an amenable number.

31728133 is a deficient number, since it is larger than the sum of its proper divisors (1).

31728133 is an equidigital number, since it uses as much as digits as its factorization.

31728133 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 31728133 is about 5632.7731181009. The cubic root of 31728133 is about 316.5785647183.

The spelling of 31728133 in words is "thirty-one million, seven hundred twenty-eight thousand, one hundred thirty-three".