31968521 has 8 divisors (see below), whose sum is σ = 34509384. Its totient is φ = 29439360.

The previous prime is 31968509. The next prime is 31968523. The reversal of 31968521 is 12586913.

It can be written as a sum of positive squares in 4 ways, for example, as 3024121 + 28944400 = 1739^2 + 5380^2 .

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 31968521 - 2⁶ = 31968457 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31968523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3251 + ... + 8631.

It is an arithmetic number, because the mean of its divisors is an integer number (4313673).

Almost surely, 2^31968521 is an apocalyptic number.

It is an amenable number.

31968521 is a deficient number, since it is larger than the sum of its proper divisors (2540863).

31968521 is a wasteful number, since it uses less digits than its factorization.

31968521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5851.

The product of its digits is 12960, while the sum is 35.

The square root of 31968521 is about 5654.0711880909. The cubic root of 31968521 is about 317.3760724935.

The spelling of 31968521 in words is "thirty-one million, nine hundred sixty-eight thousand, five hundred twenty-one".