172146509 has 2 divisors, whose sum is σ = 172146510. Its totient is φ = 172146508.

The previous prime is 172146497. The next prime is 172146547. The reversal of 172146509 is 905641271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164737225 + 7409284 = 12835^2 + 2722^2 .

It is a cyclic number.

It is not a de Polignac number, because 172146509 - 2¹⁶ = 172080973 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 (172146589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86073254 + 86073255.

It is an arithmetic number, because the mean of its divisors is an integer number (86073255).

Almost surely, 2^172146509 is an apocalyptic number.

It is an amenable number.

172146509 is a deficient number, since it is larger than the sum of its proper divisors (1).

172146509 is an equidigital number, since it uses as much as digits as its factorization.

172146509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 172146509 is about 13120.4614629212. The cubic root of 172146509 is about 556.2876349741.

The spelling of 172146509 in words is "one hundred seventy-two million, one hundred forty-six thousand, five hundred nine".