216345661 has 8 divisors (see below), whose sum is σ = 248734080. Its totient is φ = 184327728.

The previous prime is 216345637. The next prime is 216345667. The reversal of 216345661 is 166543612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 216345661 - 2⁹ = 216345149 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216345667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91366 + ... + 93703.

It is an arithmetic number, because the mean of its divisors is an integer number (31091760).

Almost surely, 2^216345661 is an apocalyptic number.

It is an amenable number.

216345661 is a deficient number, since it is larger than the sum of its proper divisors (32388419).

216345661 is a wasteful number, since it uses less digits than its factorization.

216345661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185243.

The product of its digits is 25920, while the sum is 34.

The square root of 216345661 is about 14708.6933818066. The cubic root of 216345661 is about 600.3198859062.

The spelling of 216345661 in words is "two hundred sixteen million, three hundred forty-five thousand, six hundred sixty-one".