31212131440 has 160 divisors (see below), whose sum is σ = 89660689920. Its totient is φ = 9863949312.

The previous prime is 31212131437. The next prime is 31212131471. The reversal of 31212131440 is 4413121213.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 354039 + ... + 433321.

It is an arithmetic number, because the mean of its divisors is an integer number (560379312).

Almost surely, 2^31212131440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31212131440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44830344960).

31212131440 is an abundant number, since it is smaller than the sum of its proper divisors (58448558480).

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

31212131440 is a wasteful number, since it uses less digits than its factorization.

31212131440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79359 (or 79353 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 31212131440 its reverse (4413121213), we get a palindrome (35625252653).

The spelling of 31212131440 in words is "thirty-one billion, two hundred twelve million, one hundred thirty-one thousand, four hundred forty".