31371284781 has 48 divisors (see below), whose sum is σ = 48322226160. Its totient is φ = 19543818240.

The previous prime is 31371284717. The next prime is 31371284801. The reversal of 31371284781 is 18748217313.

It can be written as a sum of positive squares in 8 ways, for example, as 917544681 + 30453740100 = 30291^2 + 174510^2 .

It is not a de Polignac number, because 31371284781 - 2⁶ = 31371284717 is a prime.

It is a super-2 number, since 2×31371284781² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31371284281) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 27786225 + ... + 27787353.

It is an arithmetic number, because the mean of its divisors is an integer number (1006713045).

Almost surely, 2^31371284781 is an apocalyptic number.

It is an amenable number.

31371284781 is a deficient number, since it is larger than the sum of its proper divisors (16950941379).

31371284781 is a wasteful number, since it uses less digits than its factorization.

31371284781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2286 (or 2283 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The spelling of 31371284781 in words is "thirty-one billion, three hundred seventy-one million, two hundred eighty-four thousand, seven hundred eighty-one".