171688493 has 2 divisors, whose sum is σ = 171688494. Its totient is φ = 171688492.

The previous prime is 171688477. The next prime is 171688501. The reversal of 171688493 is 394886171.

171688493 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134258569 + 37429924 = 11587^2 + 6118^2 .

It is a cyclic number.

It is not a de Polignac number, because 171688493 - 2⁴ = 171688477 is a prime.

It is a super-2 number, since 2×171688493² = 58953877257222098, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (171688463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85844246 + 85844247.

It is an arithmetic number, because the mean of its divisors is an integer number (85844247).

Almost surely, 2^171688493 is an apocalyptic number.

It is an amenable number.

171688493 is a deficient number, since it is larger than the sum of its proper divisors (1).

171688493 is an equidigital number, since it uses as much as digits as its factorization.

171688493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 47.

The square root of 171688493 is about 13102.9955735320. The cubic root of 171688493 is about 555.7938405922.

It can be divided in two parts, 1716 and 88493, that added together give a palindrome (90209).

The spelling of 171688493 in words is "one hundred seventy-one million, six hundred eighty-eight thousand, four hundred ninety-three".