31360321 has 2 divisors, whose sum is σ = 31360322. Its totient is φ = 31360320.

The previous prime is 31360319. The next prime is 31360331. The reversal of 31360321 is 12306313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30924721 + 435600 = 5561^2 + 660^2 .

It is an emirp because it is prime and its reverse (12306313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31360321 - 2¹ = 31360319 is a prime.

Together with 31360319, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (31360331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15680160 + 15680161.

It is an arithmetic number, because the mean of its divisors is an integer number (15680161).

Almost surely, 2^31360321 is an apocalyptic number.

It is an amenable number.

31360321 is a deficient number, since it is larger than the sum of its proper divisors (1).

31360321 is an equidigital number, since it uses as much as digits as its factorization.

31360321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 19.

The square root of 31360321 is about 5600.0286606409. The cubic root of 31360321 is about 315.3504824895.

Adding to 31360321 its reverse (12306313), we get a palindrome (43666634).

The spelling of 31360321 in words is "thirty-one million, three hundred sixty thousand, three hundred twenty-one".