121858209 has 32 divisors (see below), whose sum is σ = 205516800. Its totient is φ = 70638480.

The previous prime is 121858201. The next prime is 121858237. The reversal of 121858209 is 902858121.

It is not a de Polignac number, because 121858209 - 2³ = 121858201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121858201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2089 + ... + 15750.

It is an arithmetic number, because the mean of its divisors is an integer number (6422400).

Almost surely, 2^121858209 is an apocalyptic number.

It is an amenable number.

121858209 is a deficient number, since it is larger than the sum of its proper divisors (83658591).

121858209 is a wasteful number, since it uses less digits than its factorization.

121858209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17882 (or 17876 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 36.

The square root of 121858209 is about 11038.9405741674. The cubic root of 121858209 is about 495.7753505407.

The spelling of 121858209 in words is "one hundred twenty-one million, eight hundred fifty-eight thousand, two hundred nine".