16645612500 has 216 divisors, whose sum is σ = 57377515104. Its totient is φ = 4035000000.

The previous prime is 16645612499. The next prime is 16645612513. The reversal of 16645612500 is 521654661.

16645612500 is a `hidden beast` number, since 1 + 6 + 645 + 6 + 1 + 2 + 5 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1230775 + ... + 1244225.

It is an arithmetic number, because the mean of its divisors is an integer number (265636644).

Almost surely, 2^16645612500 is an apocalyptic number.

16645612500 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 16645612500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28688757552).

16645612500 is an abundant number, since it is smaller than the sum of its proper divisors (40731902604).

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

16645612500 is a wasteful number, since it uses less digits than its factorization.

16645612500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13497 (or 13472 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The spelling of 16645612500 in words is "sixteen billion, six hundred forty-five million, six hundred twelve thousand, five hundred".