31728047 has 8 divisors (see below), whose sum is σ = 34483680. Its totient is φ = 29017440.

The previous prime is 31728041. The next prime is 31728071. The reversal of 31728047 is 74082713.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 31728047 - 2⁴ = 31728031 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31728041) 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, 9779 + ... + 12612.

It is an arithmetic number, because the mean of its divisors is an integer number (4310460).

Almost surely, 2^31728047 is an apocalyptic number.

31728047 is a deficient number, since it is larger than the sum of its proper divisors (2755633).

31728047 is a wasteful number, since it uses less digits than its factorization.

31728047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22513.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 31728047 is about 5632.7654842005. The cubic root of 31728047 is about 316.5782786863.

The spelling of 31728047 in words is "thirty-one million, seven hundred twenty-eight thousand, forty-seven".