121535509 has 2 divisors, whose sum is σ = 121535510. Its totient is φ = 121535508.

The previous prime is 121535507. The next prime is 121535539. The reversal of 121535509 is 905535121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 110313009 + 11222500 = 10503^2 + 3350^2 .

It is a cyclic number.

It is not a de Polignac number, because 121535509 - 2¹ = 121535507 is a prime.

Together with 121535507, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121535503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60767754 + 60767755.

It is an arithmetic number, because the mean of its divisors is an integer number (60767755).

Almost surely, 2^121535509 is an apocalyptic number.

It is an amenable number.

121535509 is a deficient number, since it is larger than the sum of its proper divisors (1).

121535509 is an equidigital number, since it uses as much as digits as its factorization.

121535509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6750, while the sum is 31.

The square root of 121535509 is about 11024.3144458057. The cubic root of 121535509 is about 495.3373328957.

The spelling of 121535509 in words is "one hundred twenty-one million, five hundred thirty-five thousand, five hundred nine".