216533761 has 4 divisors (see below), whose sum is σ = 217440000. Its totient is φ = 215627524.

The previous prime is 216533719. The next prime is 216533789. The reversal of 216533761 is 167335612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216533761 - 2¹¹ = 216531713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216533701) 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, 452761 + ... + 453238.

It is an arithmetic number, because the mean of its divisors is an integer number (54360000).

Almost surely, 2^216533761 is an apocalyptic number.

It is an amenable number.

216533761 is a deficient number, since it is larger than the sum of its proper divisors (906239).

216533761 is an equidigital number, since it uses as much as digits as its factorization.

216533761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 906238.

The product of its digits is 22680, while the sum is 34.

The square root of 216533761 is about 14715.0861703219. The cubic root of 216533761 is about 600.4938166119.

The spelling of 216533761 in words is "two hundred sixteen million, five hundred thirty-three thousand, seven hundred sixty-one".