216621634768 has 320 divisors, whose sum is σ = 594270535680. Its totient is φ = 73825689600.

The previous prime is 216621634693. The next prime is 216621634783. The reversal of 216621634768 is 867436126612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 21085473 + ... + 21095743.

It is an arithmetic number, because the mean of its divisors is an integer number (1857095424).

Almost surely, 2^216621634768 is an apocalyptic number.

216621634768 is a gapful number since it is divisible by the number (28) 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 216621634768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (297135267840).

216621634768 is an abundant number, since it is smaller than the sum of its proper divisors (377648900912).

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

216621634768 is a wasteful number, since it uses less digits than its factorization.

216621634768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10386 (or 10380 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 52.

The spelling of 216621634768 in words is "two hundred sixteen billion, six hundred twenty-one million, six hundred thirty-four thousand, seven hundred sixty-eight".