31144321133221 has 4 divisors (see below), whose sum is σ = 31144514740812. Its totient is φ = 31144127525632.

The previous prime is 31144321133207. The next prime is 31144321133227. The reversal of 31144321133221 is 12233112344113.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20714741309025 + 10429579824196 = 4551345^2 + 3229486^2 .

It is a cyclic number.

It is not a de Polignac number, because 31144321133221 - 2¹⁷ = 31144321002149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31144321133227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96562300 + ... + 96884293.

It is an arithmetic number, because the mean of its divisors is an integer number (7786128685203).

Almost surely, 2^{31144321133221} is an apocalyptic number.

It is an amenable number.

31144321133221 is a deficient number, since it is larger than the sum of its proper divisors (193607591).

31144321133221 is a wasteful number, since it uses less digits than its factorization.

31144321133221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193607590.

The product of its digits is 10368, while the sum is 31.

Adding to 31144321133221 its reverse (12233112344113), we get a palindrome (43377433477334).

The spelling of 31144321133221 in words is "thirty-one trillion, one hundred forty-four billion, three hundred twenty-one million, one hundred thirty-three thousand, two hundred twenty-one".