121638841 has 9 divisors (see below), whose sum is σ = 125143213. Its totient is φ = 118230880.

The previous prime is 121638827. The next prime is 121638851. The reversal of 121638841 is 148836121.

The square root of 121638841 is 11029.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 95628841 + 26010000 = 9779^2 + 5100^2 .

It is not a de Polignac number, because 121638841 - 2⁵ = 121638809 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121638797 and 121638806.

It is not an unprimeable number, because it can be changed into a prime (121638851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 452055 + ... + 452323.

Almost surely, 2^121638841 is an apocalyptic number.

121638841 is the 11029-th square number.

121638841 is the 5515-th centered octagonal number.

It is an amenable number.

121638841 is a deficient number, since it is larger than the sum of its proper divisors (3504372).

121638841 is an frugal number, since it uses more digits than its factorization.

121638841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 310 counting only the distinct ones).

The product of its digits is 9216, while the sum is 34.

The cubic root of 121638841 is about 495.4776751397.

Multiplying 121638841 by its product of digits (9216), we get a square (1121023558656 = 1058784²).

The spelling of 121638841 in words is "one hundred twenty-one million, six hundred thirty-eight thousand, eight hundred forty-one".