216505881000 has 192 divisors, whose sum is σ = 732197353680. Its totient is φ = 57702758400.

The previous prime is 216505880993. The next prime is 216505881077. The reversal of 216505881000 is 188505612.

216505881000 is a `hidden beast` number, since 2 + 1 + 65 + 0 + 588 + 10 + 0 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 1668068964 + 214837812036 = 40842^2 + 463506^2 .

It is a super-2 number, since 2×216505881000² (a number of 23 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19227372 + ... + 19238628.

Almost surely, 2^216505881000 is an apocalyptic number.

216505881000 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 216505881000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (366098676840).

216505881000 is an abundant number, since it is smaller than the sum of its proper divisors (515691472680).

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

216505881000 is a wasteful number, since it uses less digits than its factorization.

216505881000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13421 (or 13404 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 36.

The spelling of 216505881000 in words is "two hundred sixteen billion, five hundred five million, eight hundred eighty-one thousand".