172420617 has 4 divisors (see below), whose sum is σ = 229894160. Its totient is φ = 114947076.

The previous prime is 172420609. The next prime is 172420643. The reversal of 172420617 is 716024271.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 716024271 = 3 ⋅238674757.

It is not a de Polignac number, because 172420617 - 2³ = 172420609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (172420657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28736767 + ... + 28736772.

It is an arithmetic number, because the mean of its divisors is an integer number (57473540).

Almost surely, 2^172420617 is an apocalyptic number.

It is an amenable number.

172420617 is a deficient number, since it is larger than the sum of its proper divisors (57473543).

172420617 is an equidigital number, since it uses as much as digits as its factorization.

172420617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57473542.

The product of its (nonzero) digits is 4704, while the sum is 30.

The square root of 172420617 is about 13130.9031296404. The cubic root of 172420617 is about 556.5827363791.

Adding to 172420617 its reverse (716024271), we get a palindrome (888444888).

The spelling of 172420617 in words is "one hundred seventy-two million, four hundred twenty thousand, six hundred seventeen".