216517660 has 12 divisors (see below), whose sum is σ = 454687128. Its totient is φ = 86607056.

The previous prime is 216517649. The next prime is 216517663. The reversal of 216517660 is 66715612.

It is a happy number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216517663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5412922 + ... + 5412961.

It is an arithmetic number, because the mean of its divisors is an integer number (37890594).

Almost surely, 2^216517660 is an apocalyptic number.

216517660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

216517660 is an abundant number, since it is smaller than the sum of its proper divisors (238169468).

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

216517660 is a wasteful number, since it uses less digits than its factorization.

216517660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10825892 (or 10825890 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 216517660 is about 14714.5390685539. The cubic root of 216517660 is about 600.4789324193.

The spelling of 216517660 in words is "two hundred sixteen million, five hundred seventeen thousand, six hundred sixty".