169988409 has 16 divisors (see below), whose sum is σ = 252524800. Its totient is φ = 113015088.

The previous prime is 169988393. The next prime is 169988431. The reversal of 169988409 is 904889961.

It is not a de Polignac number, because 169988409 - 2⁴ = 169988393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (169988449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1632 + ... + 18510.

It is an arithmetic number, because the mean of its divisors is an integer number (15782800).

Almost surely, 2^169988409 is an apocalyptic number.

It is an amenable number.

169988409 is a deficient number, since it is larger than the sum of its proper divisors (82536391).

169988409 is a wasteful number, since it uses less digits than its factorization.

169988409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17261 (or 17255 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The square root of 169988409 is about 13037.9603082691. The cubic root of 169988409 is about 553.9532351581.

The spelling of 169988409 in words is "one hundred sixty-nine million, nine hundred eighty-eight thousand, four hundred nine".