121638829 has 8 divisors (see below), whose sum is σ = 131677112. Its totient is φ = 111697920.

The previous prime is 121638827. The next prime is 121638851. The reversal of 121638829 is 928836121.

It can be written as a sum of positive squares in 4 ways, for example, as 19669225 + 101969604 = 4435^2 + 10098^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121638829 - 2¹ = 121638827 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121638791 and 121638800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121638827) 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 7 ways as a sum of consecutive naturals, for example, 21732 + ... + 26749.

It is an arithmetic number, because the mean of its divisors is an integer number (16459639).

Almost surely, 2^121638829 is an apocalyptic number.

It is an amenable number.

121638829 is a deficient number, since it is larger than the sum of its proper divisors (10038283).

121638829 is a wasteful number, since it uses less digits than its factorization.

121638829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48687.

The product of its digits is 41472, while the sum is 40.

The square root of 121638829 is about 11028.9994559797. Note that the first 3 decimals coincide. The cubic root of 121638829 is about 495.4776588463.

The spelling of 121638829 in words is "one hundred twenty-one million, six hundred thirty-eight thousand, eight hundred twenty-nine".