221154121 has 4 divisors (see below), whose sum is σ = 221185732. Its totient is φ = 221122512.

The previous prime is 221154079. The next prime is 221154169. The reversal of 221154121 is 121451122.

221154121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 113720896 + 107433225 = 10664^2 + 10365^2 .

It is a cyclic number.

It is not a de Polignac number, because 221154121 - 2¹⁹ = 220629833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221154191) 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, 126 + ... + 21031.

It is an arithmetic number, because the mean of its divisors is an integer number (55296433).

Almost surely, 2^221154121 is an apocalyptic number.

It is an amenable number.

221154121 is a deficient number, since it is larger than the sum of its proper divisors (31611).

221154121 is a wasteful number, since it uses less digits than its factorization.

221154121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31610.

The product of its digits is 160, while the sum is 19.

The square root of 221154121 is about 14871.2514940741. The cubic root of 221154121 is about 604.7348709661.

The spelling of 221154121 in words is "two hundred twenty-one million, one hundred fifty-four thousand, one hundred twenty-one".