172218558351509 has 2 divisors, whose sum is σ = 172218558351510. Its totient is φ = 172218558351508.

The previous prime is 172218558351467. The next prime is 172218558351527. The reversal of 172218558351509 is 905153855812271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89144849139025 + 83073709212484 = 9441655^2 + 9114478^2 .

It is a cyclic number.

It is not a de Polignac number, because 172218558351509 - 2¹⁶ = 172218558285973 is a prime.

It is a super-2 number, since 2×172218558351509² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172218558311509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86109279175754 + 86109279175755.

It is an arithmetic number, because the mean of its divisors is an integer number (86109279175755).

Almost surely, 2^{172218558351509} is an apocalyptic number.

It is an amenable number.

172218558351509 is a deficient number, since it is larger than the sum of its proper divisors (1).

172218558351509 is an equidigital number, since it uses as much as digits as its factorization.

172218558351509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240000, while the sum is 62.

The spelling of 172218558351509 in words is "one hundred seventy-two trillion, two hundred eighteen billion, five hundred fifty-eight million, three hundred fifty-one thousand, five hundred nine".