121938821 has 4 divisors (see below), whose sum is σ = 124533312. Its totient is φ = 119344332.

The previous prime is 121938787. The next prime is 121938871. The reversal of 121938821 is 128839121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121938821 - 2¹⁸ = 121676677 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121938871) 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, 1297175 + ... + 1297268.

It is an arithmetic number, because the mean of its divisors is an integer number (31133328).

Almost surely, 2^121938821 is an apocalyptic number.

It is an amenable number.

121938821 is a deficient number, since it is larger than the sum of its proper divisors (2594491).

121938821 is an equidigital number, since it uses as much as digits as its factorization.

121938821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2594490.

The product of its digits is 6912, while the sum is 35.

The square root of 121938821 is about 11042.5912267004. The cubic root of 121938821 is about 495.8846486981.

The spelling of 121938821 in words is "one hundred twenty-one million, nine hundred thirty-eight thousand, eight hundred twenty-one".