19917580540 has 96 divisors (see below), whose sum is σ = 49177497600. Its totient is φ = 6680428800.

The previous prime is 19917580499. The next prime is 19917580541. The reversal of 19917580540 is 4508571991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19917580541) 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 31 ways as a sum of consecutive naturals, for example, 6035811 + ... + 6039109.

It is an arithmetic number, because the mean of its divisors is an integer number (512265600).

Almost surely, 2^19917580540 is an apocalyptic number.

19917580540 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 19917580540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24588748800).

19917580540 is an abundant number, since it is smaller than the sum of its proper divisors (29259917060).

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

19917580540 is a wasteful number, since it uses less digits than its factorization.

19917580540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5443 (or 5441 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 49.

The spelling of 19917580540 in words is "nineteen billion, nine hundred seventeen million, five hundred eighty thousand, five hundred forty".