31121985847 has 2 divisors, whose sum is σ = 31121985848. Its totient is φ = 31121985846.

The previous prime is 31121985827. The next prime is 31121985857. The reversal of 31121985847 is 74858912113.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31121985847 - 2¹¹ = 31121983799 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31121985847.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31121985827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15560992923 + 15560992924.

It is an arithmetic number, because the mean of its divisors is an integer number (15560992924).

Almost surely, 2^31121985847 is an apocalyptic number.

31121985847 is a deficient number, since it is larger than the sum of its proper divisors (1).

31121985847 is an equidigital number, since it uses as much as digits as its factorization.

31121985847 is an evil number, because the sum of its binary digits is even.

The product of its digits is 483840, while the sum is 49.

The spelling of 31121985847 in words is "thirty-one billion, one hundred twenty-one million, nine hundred eighty-five thousand, eight hundred forty-seven".