171520478 has 4 divisors (see below), whose sum is σ = 257280720. Its totient is φ = 85760238.

The previous prime is 171520477. The next prime is 171520513. The reversal of 171520478 is 874025171.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 874025171 = 29 ⋅30138799.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (171520477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42880118 + ... + 42880121.

It is an arithmetic number, because the mean of its divisors is an integer number (64320180).

Almost surely, 2^171520478 is an apocalyptic number.

171520478 is a deficient number, since it is larger than the sum of its proper divisors (85760242).

171520478 is an equidigital number, since it uses as much as digits as its factorization.

171520478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85760241.

The product of its (nonzero) digits is 15680, while the sum is 35.

The square root of 171520478 is about 13096.5826840440. The cubic root of 171520478 is about 555.6124807773.

The spelling of 171520478 in words is "one hundred seventy-one million, five hundred twenty thousand, four hundred seventy-eight".