216161021952 has 260 divisors, whose sum is σ = 666597471936. Its totient is φ = 69726044160.

The previous prime is 216161021911. The next prime is 216161021953. The reversal of 216161021952 is 259120161612.

216161021952 is a `hidden beast` number, since 2 + 1 + 616 + 10 + 21 + 9 + 5 + 2 = 666.

It is a super-2 number, since 2×216161021952² (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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216161021953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 10274548 + ... + 10295564.

Almost surely, 2^216161021952 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216161021952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (333298735968).

216161021952 is an abundant number, since it is smaller than the sum of its proper divisors (450436449984).

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

216161021952 is an equidigital number, since it uses as much as digits as its factorization.

216161021952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21084 (or 21053 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The spelling of 216161021952 in words is "two hundred sixteen billion, one hundred sixty-one million, twenty-one thousand, nine hundred fifty-two".