216428215680 has 640 divisors, whose sum is σ = 841749084000. Its totient is φ = 52784234496.

The previous prime is 216428215673. The next prime is 216428215681. The reversal of 216428215680 is 86512824612.

216428215680 is a `hidden beast` number, since 2 + 1 + 6 + 4 + 2 + 82 + 1 + 568 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216428215681) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 28560052 + ... + 28567628.

Almost surely, 2^216428215680 is an apocalyptic number.

216428215680 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 216428215680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (420874542000).

216428215680 is an abundant number, since it is smaller than the sum of its proper divisors (625320868320).

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

216428215680 is a wasteful number, since it uses less digits than its factorization.

216428215680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7656 (or 7635 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 216428215680 in words is "two hundred sixteen billion, four hundred twenty-eight million, two hundred fifteen thousand, six hundred eighty".