209842741 has 4 divisors (see below), whose sum is σ = 213802092. Its totient is φ = 205883392.

The previous prime is 209842697. The next prime is 209842793. The reversal of 209842741 is 147248902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 147248902 = 2 ⋅73624451.

It can be written as a sum of positive squares in 2 ways, for example, as 54316900 + 155525841 = 7370^2 + 12471^2 .

It is a cyclic number.

It is not a de Polignac number, because 209842741 - 2⁹ = 209842229 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 209842741.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209848741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1979596 + ... + 1979701.

It is an arithmetic number, because the mean of its divisors is an integer number (53450523).

Almost surely, 2^209842741 is an apocalyptic number.

It is an amenable number.

209842741 is a deficient number, since it is larger than the sum of its proper divisors (3959351).

209842741 is an equidigital number, since it uses as much as digits as its factorization.

209842741 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3959350.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 209842741 is about 14485.9497790100. The cubic root of 209842741 is about 594.2437875548.

The spelling of 209842741 in words is "two hundred nine million, eight hundred forty-two thousand, seven hundred forty-one".