172542817 has 2 divisors, whose sum is σ = 172542818. Its totient is φ = 172542816.

The previous prime is 172542793. The next prime is 172542829. The reversal of 172542817 is 718245271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 92332881 + 80209936 = 9609^2 + 8956^2 .

It is an emirp because it is prime and its reverse (718245271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 172542817 - 2²³ = 164154209 is a prime.

It is not a weakly prime, because it can be changed into another prime (172542847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86271408 + 86271409.

It is an arithmetic number, because the mean of its divisors is an integer number (86271409).

Almost surely, 2^172542817 is an apocalyptic number.

It is an amenable number.

172542817 is a deficient number, since it is larger than the sum of its proper divisors (1).

172542817 is an equidigital number, since it uses as much as digits as its factorization.

172542817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31360, while the sum is 37.

The square root of 172542817 is about 13135.5554507604. Note that the first 3 decimals coincide. The cubic root of 172542817 is about 556.7141946503.

The spelling of 172542817 in words is "one hundred seventy-two million, five hundred forty-two thousand, eight hundred seventeen".