31121663 has 2 divisors, whose sum is σ = 31121664. Its totient is φ = 31121662.

The previous prime is 31121659. The next prime is 31121687. The reversal of 31121663 is 36612113.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31121663 - 2² = 31121659 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31121603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15560831 + 15560832.

It is an arithmetic number, because the mean of its divisors is an integer number (15560832).

Almost surely, 2^31121663 is an apocalyptic number.

31121663 is a deficient number, since it is larger than the sum of its proper divisors (1).

31121663 is an equidigital number, since it uses as much as digits as its factorization.

31121663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 23.

The square root of 31121663 is about 5578.6793239978. The cubic root of 31121663 is about 314.5484855609.

Adding to 31121663 its reverse (36612113), we get a palindrome (67733776).

The spelling of 31121663 in words is "thirty-one million, one hundred twenty-one thousand, six hundred sixty-three".