216717540 has 96 divisors (see below), whose sum is σ = 661946880. Its totient is φ = 52655616.

The previous prime is 216717539. The next prime is 216717607. The reversal of 216717540 is 45717612.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59862 + ... + 63378.

It is an arithmetic number, because the mean of its divisors is an integer number (6895280).

Almost surely, 2^216717540 is an apocalyptic number.

216717540 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 216717540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330973440).

216717540 is an abundant number, since it is smaller than the sum of its proper divisors (445229340).

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

216717540 is a wasteful number, since it uses less digits than its factorization.

216717540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3621 (or 3619 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 33.

The square root of 216717540 is about 14721.3294236628. The cubic root of 216717540 is about 600.6636545560.

The spelling of 216717540 in words is "two hundred sixteen million, seven hundred seventeen thousand, five hundred forty".