171491920 has 40 divisors (see below), whose sum is σ = 422176104. Its totient is φ = 64561152.

The previous prime is 171491897. The next prime is 171491951. The reversal of 171491920 is 29194171.

It can be written as a sum of positive squares in 4 ways, for example, as 26915344 + 144576576 = 5188^2 + 12024^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61689 + ... + 64408.

Almost surely, 2^171491920 is an apocalyptic number.

171491920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

171491920 is an abundant number, since it is smaller than the sum of its proper divisors (250684184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

171491920 is a wasteful number, since it uses less digits than its factorization.

171491920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126127 (or 126121 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 34.

The square root of 171491920 is about 13095.4923542416. The cubic root of 171491920 is about 555.5816427454.

The spelling of 171491920 in words is "one hundred seventy-one million, four hundred ninety-one thousand, nine hundred twenty".