216545978880 has 2560 divisors, whose sum is σ = 1052161228800. Its totient is φ = 40874803200.

The previous prime is 216545978863. The next prime is 216545978897. The reversal of 216545978880 is 88879545612.

216545978880 is a `hidden beast` number, since 2 + 1 + 6 + 545 + 9 + 7 + 8 + 8 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (216545978863) and next prime (216545978897).

It is a tau number, because it is divible by the number of its divisors (2560).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 3549934050 + ... + 3549934110.

It is an arithmetic number, because the mean of its divisors is an integer number (411000480).

Almost surely, 2^216545978880 is an apocalyptic number.

216545978880 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 216545978880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (526080614400).

216545978880 is an abundant number, since it is smaller than the sum of its proper divisors (835615249920).

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

216545978880 is a wasteful number, since it uses less digits than its factorization.

216545978880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 38707200, while the sum is 63.

The spelling of 216545978880 in words is "two hundred sixteen billion, five hundred forty-five million, nine hundred seventy-eight thousand, eight hundred eighty".