217127440 has 80 divisors (see below), whose sum is σ = 534697920. Its totient is φ = 81768960.

The previous prime is 217127423. The next prime is 217127461. The reversal of 217127440 is 44721712.

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

It is a junction number, because it is equal to n+sod(n) for n = 217127399 and 217127408.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 320382 + ... + 321058.

It is an arithmetic number, because the mean of its divisors is an integer number (6683724).

Almost surely, 2^217127440 is an apocalyptic number.

217127440 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 217127440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267348960).

217127440 is an abundant number, since it is smaller than the sum of its proper divisors (317570480).

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

217127440 is a wasteful number, since it uses less digits than its factorization.

217127440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920 (or 914 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 28.

The square root of 217127440 is about 14735.2448232121. The cubic root of 217127440 is about 601.0421148723.

The spelling of 217127440 in words is "two hundred seventeen million, one hundred twenty-seven thousand, four hundred forty".