31531201 has 4 divisors (see below), whose sum is σ = 33956692. Its totient is φ = 29105712.

The previous prime is 31531163. The next prime is 31531217. The reversal of 31531201 is 10213513.

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 3186225 + 28344976 = 1785^2 + 5324^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31531201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31531261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1212726 + ... + 1212751.

It is an arithmetic number, because the mean of its divisors is an integer number (8489173).

Almost surely, 2^31531201 is an apocalyptic number.

It is an amenable number.

31531201 is a deficient number, since it is larger than the sum of its proper divisors (2425491).

31531201 is a wasteful number, since it uses less digits than its factorization.

31531201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2425490.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 31531201 is about 5615.2649981991. The cubic root of 31531201 is about 315.9222188791.

Adding to 31531201 its reverse (10213513), we get a palindrome (41744714).

The spelling of 31531201 in words is "thirty-one million, five hundred thirty-one thousand, two hundred one".