121828221 has 6 divisors (see below), whose sum is σ = 175974110. Its totient is φ = 81218808.

The previous prime is 121828199. The next prime is 121828237. The reversal of 121828221 is 122828121.

It can be written as a sum of positive squares in only one way, i.e., 82628100 + 39200121 = 9090^2 + 6261^2 .

It is not a de Polignac number, because 121828221 - 2⁷ = 121828093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121828271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6768226 + ... + 6768243.

Almost surely, 2^121828221 is an apocalyptic number.

It is an amenable number.

121828221 is a deficient number, since it is larger than the sum of its proper divisors (54145889).

121828221 is a wasteful number, since it uses less digits than its factorization.

121828221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13536475 (or 13536472 counting only the distinct ones).

The product of its digits is 1024, while the sum is 27.

The square root of 121828221 is about 11037.5822080744. The cubic root of 121828221 is about 495.7346788698.

The spelling of 121828221 in words is "one hundred twenty-one million, eight hundred twenty-eight thousand, two hundred twenty-one".