19749789440 has 144 divisors (see below), whose sum is σ = 50914241280. Its totient is φ = 7312834560.

The previous prime is 19749789403. The next prime is 19749789443. The reversal of 19749789440 is 4498794791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19749789443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1319921 + ... + 1334799.

It is an arithmetic number, because the mean of its divisors is an integer number (353571120).

Almost surely, 2^19749789440 is an apocalyptic number.

19749789440 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 19749789440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25457120640).

19749789440 is an abundant number, since it is smaller than the sum of its proper divisors (31164451840).

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

19749789440 is a wasteful number, since it uses less digits than its factorization.

19749789440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14978 (or 14964 counting only the distinct ones).

The product of its (nonzero) digits is 18289152, while the sum is 62.

The spelling of 19749789440 in words is "nineteen billion, seven hundred forty-nine million, seven hundred eighty-nine thousand, four hundred forty".