216012161 has 4 divisors (see below), whose sum is σ = 216042324. Its totient is φ = 215982000.

The previous prime is 216012143. The next prime is 216012169. The reversal of 216012161 is 161210612.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 79566400 + 136445761 = 8920^2 + 11681^2 .

It is a cyclic number.

It is not a de Polignac number, because 216012161 - 2²² = 211817857 is a prime.

It is a super-2 number, since 2×216012161² = 93322507399779842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216012169) 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, 2471 + ... + 20931.

It is an arithmetic number, because the mean of its divisors is an integer number (54010581).

Almost surely, 2^216012161 is an apocalyptic number.

It is an amenable number.

216012161 is a deficient number, since it is larger than the sum of its proper divisors (30163).

216012161 is a wasteful number, since it uses less digits than its factorization.

216012161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30162.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 216012161 is about 14697.3521764976. The cubic root of 216012161 is about 600.0112599739.

Adding to 216012161 its reverse (161210612), we get a palindrome (377222773).

The spelling of 216012161 in words is "two hundred sixteen million, twelve thousand, one hundred sixty-one".