31440143440 has 20 divisors (see below), whose sum is σ = 73098333684. Its totient is φ = 12576057344.

The previous prime is 31440143419. The next prime is 31440143473. The reversal of 31440143440 is 4434104413.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20151505936 + 11288637504 = 141956^2 + 106248^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 31440143399 and 31440143408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196500817 + ... + 196500976.

Almost surely, 2^31440143440 is an apocalyptic number.

It is an amenable number.

31440143440 is an abundant number, since it is smaller than the sum of its proper divisors (41658190244).

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

31440143440 is a wasteful number, since it uses less digits than its factorization.

31440143440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393001806 (or 393001800 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 31440143440 its reverse (4434104413), we get a palindrome (35874247853).

The spelling of 31440143440 in words is "thirty-one billion, four hundred forty million, one hundred forty-three thousand, four hundred forty".