31321001 has 4 divisors (see below), whose sum is σ = 31598292. Its totient is φ = 31043712.

The previous prime is 31320997. The next prime is 31321013. The reversal of 31321001 is 10012313.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14707225 + 16613776 = 3835^2 + 4076^2 .

It is a cyclic number.

It is not a de Polignac number, because 31321001 - 2² = 31320997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31324001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138476 + ... + 138701.

It is an arithmetic number, because the mean of its divisors is an integer number (7899573).

Almost surely, 2^31321001 is an apocalyptic number.

It is an amenable number.

31321001 is a deficient number, since it is larger than the sum of its proper divisors (277291).

31321001 is a wasteful number, since it uses less digits than its factorization.

31321001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277290.

The product of its (nonzero) digits is 18, while the sum is 11.

The square root of 31321001 is about 5596.5168631927. The cubic root of 31321001 is about 315.2186304501.

Adding to 31321001 its reverse (10012313), we get a palindrome (41333314).

The spelling of 31321001 in words is "thirty-one million, three hundred twenty-one thousand, one".