216534261 has 8 divisors (see below), whose sum is σ = 288799744. Its totient is φ = 144312480.

The previous prime is 216534233. The next prime is 216534289. The reversal of 216534261 is 162435612.

216534261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (216534233) and next prime (216534289).

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

It is not a de Polignac number, because 216534261 - 2⁵ = 216534229 is a prime.

It is a super-2 number, since 2×216534261² = 93774172373632242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216534211) 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, 3276 + ... + 21066.

It is an arithmetic number, because the mean of its divisors is an integer number (36099968).

Almost surely, 2^216534261 is an apocalyptic number.

It is an amenable number.

216534261 is a deficient number, since it is larger than the sum of its proper divisors (72265483).

216534261 is a wasteful number, since it uses less digits than its factorization.

216534261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21851.

The product of its digits is 8640, while the sum is 30.

The square root of 216534261 is about 14715.1031596792. The cubic root of 216534261 is about 600.4942788134.

Adding to 216534261 its reverse (162435612), we get a palindrome (378969873).

The spelling of 216534261 in words is "two hundred sixteen million, five hundred thirty-four thousand, two hundred sixty-one".