19728401 has 16 divisors (see below), whose sum is σ = 24755328. Its totient is φ = 15273600.

The previous prime is 19728389. The next prime is 19728407. The reversal of 19728401 is 10482791.

It is a cyclic number.

It is not a de Polignac number, because 19728401 - 2⁶ = 19728337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (19728407) 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, 12581 + ... + 14061.

It is an arithmetic number, because the mean of its divisors is an integer number (1547208).

Almost surely, 2^19728401 is an apocalyptic number.

19728401 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

19728401 is a deficient number, since it is larger than the sum of its proper divisors (5026927).

19728401 is a wasteful number, since it uses less digits than its factorization.

19728401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1672.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 19728401 is about 4441.6664665416. Note that the first 3 decimals coincide. The cubic root of 19728401 is about 270.2074354696.

The spelling of 19728401 in words is "nineteen million, seven hundred twenty-eight thousand, four hundred one".