31243261 has 8 divisors (see below), whose sum is σ = 35968320. Its totient is φ = 26583648.

The previous prime is 31243253. The next prime is 31243279. The reversal of 31243261 is 16234213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31243261 - 2³ = 31243253 is a prime.

It is a super-2 number, since 2×31243261² = 1952282715828242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31243211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15331 + ... + 17248.

It is an arithmetic number, because the mean of its divisors is an integer number (4496040).

Almost surely, 2^31243261 is an apocalyptic number.

It is an amenable number.

31243261 is a deficient number, since it is larger than the sum of its proper divisors (4725059).

31243261 is a wasteful number, since it uses less digits than its factorization.

31243261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32723.

The product of its digits is 864, while the sum is 22.

The square root of 31243261 is about 5589.5671567663. The cubic root of 31243261 is about 314.9576192248.

Adding to 31243261 its reverse (16234213), we get a palindrome (47477474).

The spelling of 31243261 in words is "thirty-one million, two hundred forty-three thousand, two hundred sixty-one".