31531263361 has 4 divisors (see below), whose sum is σ = 33956745172. Its totient is φ = 29105781552.

The previous prime is 31531263353. The next prime is 31531263367. The reversal of 31531263361 is 16336213513.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16336213513 = 4799 ⋅3404087.

It can be written as a sum of positive squares in 2 ways, for example, as 4382440000 + 27148823361 = 66200^2 + 164769^2 .

It is a cyclic number.

It is not a de Polignac number, because 31531263361 - 2³ = 31531263353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31531263367) 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, 1212740886 + ... + 1212740911.

It is an arithmetic number, because the mean of its divisors is an integer number (8489186293).

Almost surely, 2^31531263361 is an apocalyptic number.

It is an amenable number.

31531263361 is a deficient number, since it is larger than the sum of its proper divisors (2425481811).

31531263361 is a wasteful number, since it uses less digits than its factorization.

31531263361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2425481810.

The product of its digits is 29160, while the sum is 34.

Adding to 31531263361 its reverse (16336213513), we get a palindrome (47867476874).

The spelling of 31531263361 in words is "thirty-one billion, five hundred thirty-one million, two hundred sixty-three thousand, three hundred sixty-one".