31221001241 has 4 divisors (see below), whose sum is σ = 31223536932. Its totient is φ = 31218465552.

The previous prime is 31221001223. The next prime is 31221001283. The reversal of 31221001241 is 14210012213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 14210012213 = 3923 ⋅3622231.

It can be written as a sum of positive squares in 2 ways, for example, as 25478544400 + 5742456841 = 159620^2 + 75779^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31221001241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31221001291) 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 in 3 ways as a sum of consecutive naturals, for example, 1249286 + ... + 1274031.

It is an arithmetic number, because the mean of its divisors is an integer number (7805884233).

Almost surely, 2^31221001241 is an apocalyptic number.

It is an amenable number.

31221001241 is a deficient number, since it is larger than the sum of its proper divisors (2535691).

31221001241 is a wasteful number, since it uses less digits than its factorization.

31221001241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2535690.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 31221001241 its reverse (14210012213), we get a palindrome (45431013454).

The spelling of 31221001241 in words is "thirty-one billion, two hundred twenty-one million, one thousand, two hundred forty-one".