31181201 has 2 divisors, whose sum is σ = 31181202. Its totient is φ = 31181200.

The previous prime is 31181173. The next prime is 31181203. The reversal of 31181201 is 10218113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18931201 + 12250000 = 4351^2 + 3500^2 .

It is an emirp because it is prime and its reverse (10218113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31181201 - 2¹⁴ = 31164817 is a prime.

It is a Sophie Germain prime.

Together with 31181203, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31181201.

It is not a weakly prime, because it can be changed into another prime (31181203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15590600 + 15590601.

It is an arithmetic number, because the mean of its divisors is an integer number (15590601).

Almost surely, 2^31181201 is an apocalyptic number.

It is an amenable number.

31181201 is a deficient number, since it is larger than the sum of its proper divisors (1).

31181201 is an equidigital number, since it uses as much as digits as its factorization.

31181201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 17.

The square root of 31181201 is about 5584.0129835093. The cubic root of 31181201 is about 314.7489424795.

Adding to 31181201 its reverse (10218113), we get a palindrome (41399314).

The spelling of 31181201 in words is "thirty-one million, one hundred eighty-one thousand, two hundred one".