19816669440 has 288 divisors, whose sum is σ = 71199878400. Its totient is φ = 5283698688.

The previous prime is 19816669363. The next prime is 19816669487. The reversal of 19816669440 is 4496661891.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2795821 + ... + 2802899.

It is an arithmetic number, because the mean of its divisors is an integer number (247221800).

Almost surely, 2^19816669440 is an apocalyptic number.

19816669440 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 19816669440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35599939200).

19816669440 is an abundant number, since it is smaller than the sum of its proper divisors (51383208960).

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

19816669440 is an frugal number, since it uses more digits than its factorization.

19816669440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7121 (or 7089 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The spelling of 19816669440 in words is "nineteen billion, eight hundred sixteen million, six hundred sixty-nine thousand, four hundred forty".