121805789 has 24 divisors (see below), whose sum is σ = 151571520. Its totient is φ = 95618880.

The previous prime is 121805773. The next prime is 121805791. The reversal of 121805789 is 987508121.

It is not a de Polignac number, because 121805789 - 2⁴ = 121805773 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 (121805689) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 127337 + ... + 128289.

It is an arithmetic number, because the mean of its divisors is an integer number (6315480).

Almost surely, 2^121805789 is an apocalyptic number.

121805789 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

121805789 is a deficient number, since it is larger than the sum of its proper divisors (29765731).

121805789 is an equidigital number, since it uses as much as digits as its factorization.

121805789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1041 (or 1010 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 41.

The square root of 121805789 is about 11036.5659967220. The cubic root of 121805789 is about 495.7042507724.

The spelling of 121805789 in words is "one hundred twenty-one million, eight hundred five thousand, seven hundred eighty-nine".