19728380 has 72 divisors (see below), whose sum is σ = 49469616. Its totient is φ = 6585600.

The previous prime is 19728377. The next prime is 19728389. The reversal of 19728380 is 8382791.

19728380 = T₁ + T₂ + ... + T₄₉₀.

19728380 is a nontrivial binomial coefficient, being equal to C(492, 3).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19728389) by changing a digit.

It is the 490-th tetrahedral number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39935 + ... + 40425.

It is an arithmetic number, because the mean of its divisors is an integer number (687078).

Almost surely, 2^19728380 is an apocalyptic number.

19728380 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 19728380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24734808).

19728380 is an abundant number, since it is smaller than the sum of its proper divisors (29741236).

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

19728380 is a wasteful number, since it uses less digits than its factorization.

19728380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 555 (or 546 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 19728380 is about 4441.6641025634. The cubic root of 19728380 is about 270.2073395950.

The spelling of 19728380 in words is "nineteen million, seven hundred twenty-eight thousand, three hundred eighty".