19791433728 has 780 divisors, whose sum is σ = 71181592020. Its totient is φ = 5449973760.

The previous prime is 19791433721. The next prime is 19791433741. The reversal of 19791433728 is 82733419791.

It can be written as a sum of positive squares in 2 ways, for example, as 13006946304 + 6784487424 = 114048^2 + 82368^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19791433721) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 682463218 + ... + 682463246.

Almost surely, 2^19791433728 is an apocalyptic number.

19791433728 is a gapful number since it is divisible by the number (18) 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 19791433728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35590796010).

19791433728 is an abundant number, since it is smaller than the sum of its proper divisors (51390158292).

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

19791433728 is a wasteful number, since it uses less digits than its factorization.

19791433728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 62 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 54.

The spelling of 19791433728 in words is "nineteen billion, seven hundred ninety-one million, four hundred thirty-three thousand, seven hundred twenty-eight".