209478133 has 4 divisors (see below), whose sum is σ = 209525260. Its totient is φ = 209431008.

The previous prime is 209478109. The next prime is 209478161. The reversal of 209478133 is 331874902.

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 41049649 + 168428484 = 6407^2 + 12978^2 .

It is a cyclic number.

It is not a de Polignac number, because 209478133 - 2²¹ = 207380981 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 209478092 and 209478101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209478163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16110 + ... + 26047.

It is an arithmetic number, because the mean of its divisors is an integer number (52381315).

Almost surely, 2^209478133 is an apocalyptic number.

It is an amenable number.

209478133 is a deficient number, since it is larger than the sum of its proper divisors (47127).

209478133 is an equidigital number, since it uses as much as digits as its factorization.

209478133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47126.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 209478133 is about 14473.3594234373. The cubic root of 209478133 is about 593.8994159442.

The spelling of 209478133 in words is "two hundred nine million, four hundred seventy-eight thousand, one hundred thirty-three".