19728340 has 12 divisors (see below), whose sum is σ = 41429556. Its totient is φ = 7891328.

The previous prime is 19728337. The next prime is 19728367. The reversal of 19728340 is 4382791.

It can be written as a sum of positive squares in 2 ways, for example, as 11410884 + 8317456 = 3378^2 + 2884^2 .

It is a junction number, because it is equal to n+sod(n) for n = 19728296 and 19728305.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 493189 + ... + 493228.

It is an arithmetic number, because the mean of its divisors is an integer number (3452463).

Almost surely, 2^19728340 is an apocalyptic number.

19728340 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19728340 is an abundant number, since it is smaller than the sum of its proper divisors (21701216).

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

19728340 is a wasteful number, since it uses less digits than its factorization.

19728340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986426 (or 986424 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 19728340 is about 4441.6595997442. The cubic root of 19728340 is about 270.2071569765.

The spelling of 19728340 in words is "nineteen million, seven hundred twenty-eight thousand, three hundred forty".