31218805240 has 64 divisors (see below), whose sum is σ = 80293924800. Its totient is φ = 10701324288.

The previous prime is 31218805237. The next prime is 31218805243. The reversal of 31218805240 is 4250881213.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (31218805237) and next prime (31218805243).

It is a super-2 number, since 2×31218805240² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31218805196 and 31218805205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31218805243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1819582 + ... + 1836658.

It is an arithmetic number, because the mean of its divisors is an integer number (1254592575).

Almost surely, 2^31218805240 is an apocalyptic number.

It is an amenable number.

31218805240 is an abundant number, since it is smaller than the sum of its proper divisors (49075119560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31218805240 is a wasteful number, since it uses less digits than its factorization.

31218805240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23624 (or 23620 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 34.

The spelling of 31218805240 in words is "thirty-one billion, two hundred eighteen million, eight hundred five thousand, two hundred forty".