121855009 has 2 divisors, whose sum is σ = 121855010. Its totient is φ = 121855008.

The previous prime is 121854983. The next prime is 121855033. The reversal of 121855009 is 900558121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68973025 + 52881984 = 8305^2 + 7272^2 .

It is a cyclic number.

It is not a de Polignac number, because 121855009 - 2¹³ = 121846817 is a prime.

It is not a weakly prime, because it can be changed into another prime (121855049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60927504 + 60927505.

It is an arithmetic number, because the mean of its divisors is an integer number (60927505).

Almost surely, 2^121855009 is an apocalyptic number.

It is an amenable number.

121855009 is a deficient number, since it is larger than the sum of its proper divisors (1).

121855009 is an equidigital number, since it uses as much as digits as its factorization.

121855009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 121855009 is about 11038.7956317707. The cubic root of 121855009 is about 495.7710108112.

The spelling of 121855009 in words is "one hundred twenty-one million, eight hundred fifty-five thousand, nine".