121725509 has 2 divisors, whose sum is σ = 121725510. Its totient is φ = 121725508.

The previous prime is 121725493. The next prime is 121725553. The reversal of 121725509 is 905527121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 109788484 + 11937025 = 10478^2 + 3455^2 .

It is a cyclic number.

It is not a de Polignac number, because 121725509 - 2⁴ = 121725493 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121725589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60862754 + 60862755.

It is an arithmetic number, because the mean of its divisors is an integer number (60862755).

Almost surely, 2^121725509 is an apocalyptic number.

It is an amenable number.

121725509 is a deficient number, since it is larger than the sum of its proper divisors (1).

121725509 is an equidigital number, since it uses as much as digits as its factorization.

121725509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6300, while the sum is 32.

The square root of 121725509 is about 11032.9283963959. The cubic root of 121725509 is about 495.5953235927.

The spelling of 121725509 in words is "one hundred twenty-one million, seven hundred twenty-five thousand, five hundred nine".