19431320040 has 576 divisors, whose sum is σ = 73462671360. Its totient is φ = 4585351680.

The previous prime is 19431320021. The next prime is 19431320047. The reversal of 19431320040 is 4002313491.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 19431319986 and 19431320013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19431320047) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 153002457 + ... + 153002583.

It is an arithmetic number, because the mean of its divisors is an integer number (127539360).

Almost surely, 2^19431320040 is an apocalyptic number.

19431320040 is a gapful number since it is divisible by the number (10) 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 19431320040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36731335680).

19431320040 is an abundant number, since it is smaller than the sum of its proper divisors (54031351320).

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

19431320040 is a wasteful number, since it uses less digits than its factorization.

19431320040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The spelling of 19431320040 in words is "nineteen billion, four hundred thirty-one million, three hundred twenty thousand, forty".