217064043440 has 80 divisors (see below), whose sum is σ = 510183694368. Its totient is φ = 85880229888.

The previous prime is 217064043409. The next prime is 217064043457. The reversal of 217064043440 is 44340460712.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 217064043440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5570264 + ... + 5609096.

Almost surely, 2^217064043440 is an apocalyptic number.

217064043440 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 217064043440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (255091847184).

217064043440 is an abundant number, since it is smaller than the sum of its proper divisors (293119650928).

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

217064043440 is a wasteful number, since it uses less digits than its factorization.

217064043440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39606 (or 39600 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 35.

The spelling of 217064043440 in words is "two hundred seventeen billion, sixty-four million, forty-three thousand, four hundred forty".