19499640 has 64 divisors (see below), whose sum is σ = 59875200. Its totient is φ = 5077632.

The previous prime is 19499639. The next prime is 19499647. The reversal of 19499640 is 4699491.

It is a junction number, because it is equal to n+sod(n) for n = 19499592 and 19499601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19499647) 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 15 ways as a sum of consecutive naturals, for example, 3271 + ... + 7049.

It is an arithmetic number, because the mean of its divisors is an integer number (935550).

Almost surely, 2^19499640 is an apocalyptic number.

19499640 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 19499640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29937600).

19499640 is an abundant number, since it is smaller than the sum of its proper divisors (40375560).

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

19499640 is a wasteful number, since it uses less digits than its factorization.

19499640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3836 (or 3832 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 42.

The square root of 19499640 is about 4415.8396710026. The cubic root of 19499640 is about 269.1589742211.

The spelling of 19499640 in words is "nineteen million, four hundred ninety-nine thousand, six hundred forty".