209155145 has 8 divisors (see below), whose sum is σ = 257108040. Its totient is φ = 163242880.

The previous prime is 209155099. The next prime is 209155159. The reversal of 209155145 is 541551902.

It can be written as a sum of positive squares in 4 ways, for example, as 34703881 + 174451264 = 5891^2 + 13208^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 209155145 - 2⁸ = 209154889 is a prime.

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, 509930 + ... + 510339.

It is an arithmetic number, because the mean of its divisors is an integer number (32138505).

Almost surely, 2^209155145 is an apocalyptic number.

It is an amenable number.

209155145 is a deficient number, since it is larger than the sum of its proper divisors (47952895).

209155145 is a wasteful number, since it uses less digits than its factorization.

209155145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020315.

The product of its (nonzero) digits is 9000, while the sum is 32.

The square root of 209155145 is about 14462.1971014089. The cubic root of 209155145 is about 593.5940204124.

The spelling of 209155145 in words is "two hundred nine million, one hundred fifty-five thousand, one hundred forty-five".