170787121 has 6 divisors (see below), whose sum is σ = 178536050. Its totient is φ = 163361088.

The previous prime is 170787107. The next prime is 170787137. The reversal of 170787121 is 121787071.

It can be written as a sum of positive squares in only one way, i.e., 170668096 + 119025 = 13064^2 + 345^2 .

It is not a de Polignac number, because 170787121 - 2¹⁷ = 170656049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (170787161) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 160896 + ... + 161953.

Almost surely, 2^170787121 is an apocalyptic number.

It is an amenable number.

170787121 is a deficient number, since it is larger than the sum of its proper divisors (7748929).

170787121 is an equidigital number, since it uses as much as digits as its factorization.

170787121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322895 (or 322872 counting only the distinct ones).

The product of its (nonzero) digits is 5488, while the sum is 34.

The square root of 170787121 is about 13068.5546637721. The cubic root of 170787121 is about 554.8194862446.

Subtracting from 170787121 its reverse (121787071), we obtain a triangular number (49000050 = T₉₈₉₉).

The spelling of 170787121 in words is "one hundred seventy million, seven hundred eighty-seven thousand, one hundred twenty-one".