31200319981 has 2 divisors, whose sum is σ = 31200319982. Its totient is φ = 31200319980.

The previous prime is 31200319949. The next prime is 31200320089. The reversal of 31200319981 is 18991300213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30453391081 + 746928900 = 174509^2 + 27330^2 .

It is an emirp because it is prime and its reverse (18991300213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31200319981 - 2⁵ = 31200319949 is a prime.

It is a super-2 number, since 2×31200319981² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 31200319981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31200319901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15600159990 + 15600159991.

It is an arithmetic number, because the mean of its divisors is an integer number (15600159991).

Almost surely, 2^31200319981 is an apocalyptic number.

It is an amenable number.

31200319981 is a deficient number, since it is larger than the sum of its proper divisors (1).

31200319981 is an equidigital number, since it uses as much as digits as its factorization.

31200319981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 37.

The spelling of 31200319981 in words is "thirty-one billion, two hundred million, three hundred nineteen thousand, nine hundred eighty-one".