19744140 has 96 divisors (see below), whose sum is σ = 63080640. Its totient is φ = 4571136.

The previous prime is 19744133. The next prime is 19744141. The reversal of 19744140 is 4144791.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 19744098 and 19744107.

It is not an unprimeable number, because it can be changed into a prime (19744141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12516 + ... + 14004.

It is an arithmetic number, because the mean of its divisors is an integer number (657090).

Almost surely, 2^19744140 is an apocalyptic number.

19744140 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 19744140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31540320).

19744140 is an abundant number, since it is smaller than the sum of its proper divisors (43336500).

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

19744140 is a wasteful number, since it uses less digits than its factorization.

19744140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1531 (or 1529 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 19744140 is about 4443.4378582354. The cubic root of 19744140 is about 270.2792720804.

The spelling of 19744140 in words is "nineteen million, seven hundred forty-four thousand, one hundred forty".