19853440 has 64 divisors (see below), whose sum is σ = 48274560. Its totient is φ = 7805952.

The previous prime is 19853437. The next prime is 19853459. The reversal of 19853440 is 4435891.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 19853396 and 19853405.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42649 + ... + 43111.

It is an arithmetic number, because the mean of its divisors is an integer number (754290).

Almost surely, 2^19853440 is an apocalyptic number.

19853440 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 19853440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24137280).

19853440 is an abundant number, since it is smaller than the sum of its proper divisors (28421120).

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

19853440 is an equidigital number, since it uses as much as digits as its factorization.

19853440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 549 (or 537 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 19853440 is about 4455.7199193845. The cubic root of 19853440 is about 270.7770937005. Note that the first 3 decimals are identical.

The spelling of 19853440 in words is "nineteen million, eight hundred fifty-three thousand, four hundred forty".