31106521 has 2 divisors, whose sum is σ = 31106522. Its totient is φ = 31106520.

The previous prime is 31106513. The next prime is 31106533. The reversal of 31106521 is 12560113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24403600 + 6702921 = 4940^2 + 2589^2 .

It is a cyclic number.

It is not a de Polignac number, because 31106521 - 2³ = 31106513 is a prime.

It is not a weakly prime, because it can be changed into another prime (31106561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15553260 + 15553261.

It is an arithmetic number, because the mean of its divisors is an integer number (15553261).

Almost surely, 2^31106521 is an apocalyptic number.

It is an amenable number.

31106521 is a deficient number, since it is larger than the sum of its proper divisors (1).

31106521 is an equidigital number, since it uses as much as digits as its factorization.

31106521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 31106521 is about 5577.3220276401. The cubic root of 31106521 is about 314.4974635892.

Adding to 31106521 its reverse (12560113), we get a palindrome (43666634).

The spelling of 31106521 in words is "thirty-one million, one hundred six thousand, five hundred twenty-one".