31821395443 has 2 divisors, whose sum is σ = 31821395444. Its totient is φ = 31821395442.

The previous prime is 31821395401. The next prime is 31821395483. The reversal of 31821395443 is 34459312813.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31821395443 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31821395443.

It is not a weakly prime, because it can be changed into another prime (31821395483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15910697721 + 15910697722.

It is an arithmetic number, because the mean of its divisors is an integer number (15910697722).

Almost surely, 2^31821395443 is an apocalyptic number.

31821395443 is a deficient number, since it is larger than the sum of its proper divisors (1).

31821395443 is an equidigital number, since it uses as much as digits as its factorization.

31821395443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 311040, while the sum is 43.

The spelling of 31821395443 in words is "thirty-one billion, eight hundred twenty-one million, three hundred ninety-five thousand, four hundred forty-three".