31363621 has 2 divisors, whose sum is σ = 31363622. Its totient is φ = 31363620.

The previous prime is 31363613. The next prime is 31363649. The reversal of 31363621 is 12636313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31192225 + 171396 = 5585^2 + 414^2 .

It is a cyclic number.

It is not a de Polignac number, because 31363621 - 2³ = 31363613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31363721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15681810 + 15681811.

It is an arithmetic number, because the mean of its divisors is an integer number (15681811).

Almost surely, 2^31363621 is an apocalyptic number.

It is an amenable number.

31363621 is a deficient number, since it is larger than the sum of its proper divisors (1).

31363621 is an equidigital number, since it uses as much as digits as its factorization.

31363621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1944, while the sum is 25.

The square root of 31363621 is about 5600.3232942394. The cubic root of 31363621 is about 315.3615433892.

Adding to 31363621 its reverse (12636313), we get a palindrome (43999934).

The spelling of 31363621 in words is "thirty-one million, three hundred sixty-three thousand, six hundred twenty-one".