209454491 has 4 divisors (see below), whose sum is σ = 218561232. Its totient is φ = 200347752.

The previous prime is 209454481. The next prime is 209454503. The reversal of 209454491 is 194454902.

209454491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 194454902 = 2 ⋅97227451.

It is a cyclic number.

It is not a de Polignac number, because 209454491 - 2¹⁰ = 209453467 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (209454451) 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, 4553336 + ... + 4553381.

It is an arithmetic number, because the mean of its divisors is an integer number (54640308).

Almost surely, 2^209454491 is an apocalyptic number.

209454491 is a deficient number, since it is larger than the sum of its proper divisors (9106741).

209454491 is an equidigital number, since it uses as much as digits as its factorization.

209454491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9106740.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 209454491 is about 14472.5426584274. The cubic root of 209454491 is about 593.8770723260.

The spelling of 209454491 in words is "two hundred nine million, four hundred fifty-four thousand, four hundred ninety-one".