21616028500 has 96 divisors (see below), whose sum is σ = 52597569024. Its totient is φ = 7693040000.

The previous prime is 21616028443. The next prime is 21616028527. The reversal of 21616028500 is 582061612.

It is a super-2 number, since 2×21616028500² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 216690 + ... + 300310.

It is an arithmetic number, because the mean of its divisors is an integer number (547891344).

Almost surely, 2^21616028500 is an apocalyptic number.

21616028500 is a gapful number since it is divisible by the number (20) 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 21616028500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26298784512).

21616028500 is an abundant number, since it is smaller than the sum of its proper divisors (30981540524).

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

21616028500 is a wasteful number, since it uses less digits than its factorization.

21616028500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83698 (or 83686 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The spelling of 21616028500 in words is "twenty-one billion, six hundred sixteen million, twenty-eight thousand, five hundred".