16645519440 has 600 divisors, whose sum is σ = 65436285024. Its totient is φ = 3905107200.

The previous prime is 16645519403. The next prime is 16645519459. The reversal of 16645519440 is 4491554661.

16645519440 is a `hidden beast` number, since 1 + 6 + 6 + 4 + 551 + 94 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 536952225 + ... + 536952255.

Almost surely, 2^16645519440 is an apocalyptic number.

16645519440 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 16645519440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32718142512).

16645519440 is an abundant number, since it is smaller than the sum of its proper divisors (48790765584).

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

16645519440 is an frugal number, since it uses more digits than its factorization.

16645519440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113 (or 52 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 16645519440 in words is "sixteen billion, six hundred forty-five million, five hundred nineteen thousand, four hundred forty".