171891320072 has 16 divisors (see below), whose sum is σ = 323633557500. Its totient is φ = 85589038080.

The previous prime is 171891320017. The next prime is 171891320087. The reversal of 171891320072 is 270023198171.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 169524886756 + 2366433316 = 411734^2 + 48646^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44575697 + ... + 44579552.

Almost surely, 2^171891320072 is an apocalyptic number.

It is an amenable number.

171891320072 is a deficient number, since it is larger than the sum of its proper divisors (151742237428).

171891320072 is a wasteful number, since it uses less digits than its factorization.

171891320072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89155496 (or 89155492 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 41.

The spelling of 171891320072 in words is "one hundred seventy-one billion, eight hundred ninety-one million, three hundred twenty thousand, seventy-two".