209185045 has 4 divisors (see below), whose sum is σ = 251022060. Its totient is φ = 167348032.

The previous prime is 209185037. The next prime is 209185057. The reversal of 209185045 is 540581902.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30935844 + 178249201 = 5562^2 + 13351^2 .

It is a cyclic number.

It is not a de Polignac number, because 209185045 - 2³ = 209185037 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 209185045.

It is a congruent number.

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, 20918500 + ... + 20918509.

It is an arithmetic number, because the mean of its divisors is an integer number (62755515).

Almost surely, 2^209185045 is an apocalyptic number.

It is an amenable number.

209185045 is a deficient number, since it is larger than the sum of its proper divisors (41837015).

209185045 is an equidigital number, since it uses as much as digits as its factorization.

209185045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41837014.

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 209185045 is about 14463.2307939824. The cubic root of 209185045 is about 593.6223050231.

The spelling of 209185045 in words is "two hundred nine million, one hundred eighty-five thousand, forty-five".