228221920161 has 24 divisors (see below), whose sum is σ = 349080661800. Its totient is φ = 143183556096.

The previous prime is 228221920103. The next prime is 228221920211. The reversal of 228221920161 is 161029122822.

228221920161 is a `hidden beast` number, since 2 + 282 + 219 + 2 + 0 + 161 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 91540133136 + 136681787025 = 302556^2 + 369705^2 .

It is not a de Polignac number, because 228221920161 - 2¹⁵ = 228221887393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (228221920261) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1553515 + ... + 1694063.

It is an arithmetic number, because the mean of its divisors is an integer number (14545027575).

Almost surely, 2^228221920161 is an apocalyptic number.

It is an amenable number.

228221920161 is a deficient number, since it is larger than the sum of its proper divisors (120858741639).

228221920161 is a wasteful number, since it uses less digits than its factorization.

228221920161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151185 (or 151182 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The spelling of 228221920161 in words is "two hundred twenty-eight billion, two hundred twenty-one million, nine hundred twenty thousand, one hundred sixty-one".