121706509 has 2 divisors, whose sum is σ = 121706510. Its totient is φ = 121706508.

The previous prime is 121706483. The next prime is 121706561. The reversal of 121706509 is 905607121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107433225 + 14273284 = 10365^2 + 3778^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121706509 is a prime.

It is a zygodrome in base 3.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121706569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60853254 + 60853255.

It is an arithmetic number, because the mean of its divisors is an integer number (60853255).

Almost surely, 2^121706509 is an apocalyptic number.

It is an amenable number.

121706509 is a deficient number, since it is larger than the sum of its proper divisors (1).

121706509 is an equidigital number, since it uses as much as digits as its factorization.

121706509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3780, while the sum is 31.

The square root of 121706509 is about 11032.0673040006. The cubic root of 121706509 is about 495.5695366091.

The spelling of 121706509 in words is "one hundred twenty-one million, seven hundred six thousand, five hundred nine".