31644517243 has 2 divisors, whose sum is σ = 31644517244. Its totient is φ = 31644517242.

The previous prime is 31644517237. The next prime is 31644517283. The reversal of 31644517243 is 34271544613.

It is an a-pointer prime, because the next prime (31644517283) can be obtained adding 31644517243 to its sum of digits (40).

It is a weak prime.

It is an emirp because it is prime and its reverse (34271544613) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31644517243 - 2¹³ = 31644509051 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31644517196 and 31644517205.

It is not a weakly prime, because it can be changed into another prime (31644517283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15822258621 + 15822258622.

It is an arithmetic number, because the mean of its divisors is an integer number (15822258622).

Almost surely, 2^31644517243 is an apocalyptic number.

31644517243 is a deficient number, since it is larger than the sum of its proper divisors (1).

31644517243 is an equidigital number, since it uses as much as digits as its factorization.

31644517243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 40.

The spelling of 31644517243 in words is "thirty-one billion, six hundred forty-four million, five hundred seventeen thousand, two hundred forty-three".