121838821 has 8 divisors (see below), whose sum is σ = 131475960. Its totient is φ = 112239552.

The previous prime is 121838809. The next prime is 121838837. The reversal of 121838821 is 128838121.

It can be written as a sum of positive squares in 4 ways, for example, as 7049025 + 114789796 = 2655^2 + 10714^2 .

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 121838821 - 2⁵ = 121838789 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 (121838851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2590 + ... + 15823.

It is an arithmetic number, because the mean of its divisors is an integer number (16434495).

Almost surely, 2^121838821 is an apocalyptic number.

It is an amenable number.

121838821 is a deficient number, since it is larger than the sum of its proper divisors (9637139).

121838821 is a wasteful number, since it uses less digits than its factorization.

121838821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18935.

The product of its digits is 6144, while the sum is 34.

The square root of 121838821 is about 11038.0623752541. The cubic root of 121838821 is about 495.7490560399.

The spelling of 121838821 in words is "one hundred twenty-one million, eight hundred thirty-eight thousand, eight hundred twenty-one".