209091242 has 4 divisors (see below), whose sum is σ = 313636866. Its totient is φ = 104545620.

The previous prime is 209091227. The next prime is 209091251. The reversal of 209091242 is 242190902.

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

It can be written as a sum of positive squares in only one way, i.e., 209062681 + 28561 = 14459^2 + 169^2 .

It is a super-2 number, since 2×209091242² = 87438294962205128, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52272809 + ... + 52272812.

Almost surely, 2^209091242 is an apocalyptic number.

209091242 is a deficient number, since it is larger than the sum of its proper divisors (104545624).

209091242 is a wasteful number, since it uses less digits than its factorization.

209091242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104545623.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 209091242 is about 14459.9876210182. The cubic root of 209091242 is about 593.5335608231.

The spelling of 209091242 in words is "two hundred nine million, ninety-one thousand, two hundred forty-two".