31145761 has 4 divisors (see below), whose sum is σ = 31307332. Its totient is φ = 30984192.

The previous prime is 31145753. The next prime is 31145771. The reversal of 31145761 is 16754113.

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 21566736 + 9579025 = 4644^2 + 3095^2 .

It is a cyclic number.

It is not a de Polignac number, because 31145761 - 2³ = 31145753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31145701) 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, 80496 + ... + 80881.

It is an arithmetic number, because the mean of its divisors is an integer number (7826833).

Almost surely, 2^31145761 is an apocalyptic number.

It is an amenable number.

31145761 is a deficient number, since it is larger than the sum of its proper divisors (161571).

31145761 is a wasteful number, since it uses less digits than its factorization.

31145761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161570.

The product of its digits is 2520, while the sum is 28.

The square root of 31145761 is about 5580.8387362474. The cubic root of 31145761 is about 314.6296512515.

Adding to 31145761 its reverse (16754113), we get a palindrome (47899874).

The spelling of 31145761 in words is "thirty-one million, one hundred forty-five thousand, seven hundred sixty-one".