16505857620 has 768 divisors, whose sum is σ = 64326205440. Its totient is φ = 3476805120.

The previous prime is 16505857597. The next prime is 16505857661. The reversal of 16505857620 is 2675850561.

16505857620 is a `hidden beast` number, since 1 + 6 + 5 + 0 + 58 + 576 + 20 = 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 255 ways as a sum of consecutive naturals, for example, 351188437 + ... + 351188483.

It is an arithmetic number, because the mean of its divisors is an integer number (83758080).

Almost surely, 2^16505857620 is an apocalyptic number.

16505857620 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 16505857620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32163102720).

16505857620 is an abundant number, since it is smaller than the sum of its proper divisors (47820347820).

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

16505857620 is a wasteful number, since it uses less digits than its factorization.

16505857620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 504000, while the sum is 45.

The spelling of 16505857620 in words is "sixteen billion, five hundred five million, eight hundred fifty-seven thousand, six hundred twenty".