31423405440 has 512 divisors, whose sum is σ = 119070720000. Its totient is φ = 6897623040.

The previous prime is 31423405411. The next prime is 31423405441. The reversal of 31423405440 is 4450432413.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 31423405398 and 31423405407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31423405441) 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 63 ways as a sum of consecutive naturals, for example, 82911171 + ... + 82911549.

It is an arithmetic number, because the mean of its divisors is an integer number (232560000).

Almost surely, 2^31423405440 is an apocalyptic number.

31423405440 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31423405440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59535360000).

31423405440 is an abundant number, since it is smaller than the sum of its proper divisors (87647314560).

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

31423405440 is a wasteful number, since it uses less digits than its factorization.

31423405440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638 (or 626 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 30.

Adding to 31423405440 its reverse (4450432413), we get a palindrome (35873837853).

The spelling of 31423405440 in words is "thirty-one billion, four hundred twenty-three million, four hundred five thousand, four hundred forty".