216661146520 has 128 divisors (see below), whose sum is σ = 603001728000. Its totient is φ = 68224882176.

The previous prime is 216661146509. The next prime is 216661146547. The reversal of 216661146520 is 25641166612.

It is a super-2 number, since 2×216661146520² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 574807 + ... + 873913.

It is an arithmetic number, because the mean of its divisors is an integer number (4710951000).

Almost surely, 2^216661146520 is an apocalyptic number.

216661146520 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 216661146520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (301500864000).

216661146520 is an abundant number, since it is smaller than the sum of its proper divisors (386340581480).

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

216661146520 is a wasteful number, since it uses less digits than its factorization.

216661146520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299337 (or 299333 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The spelling of 216661146520 in words is "two hundred sixteen billion, six hundred sixty-one million, one hundred forty-six thousand, five hundred twenty".