208561949 has 4 divisors (see below), whose sum is σ = 211419036. Its totient is φ = 205704864.

The previous prime is 208561937. The next prime is 208561973. The reversal of 208561949 is 949165802.

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 167832025 + 40729924 = 12955^2 + 6382^2 .

It is a cyclic number.

It is not a de Polignac number, because 208561949 - 2⁸ = 208561693 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208561909) 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, 1428434 + ... + 1428579.

It is an arithmetic number, because the mean of its divisors is an integer number (52854759).

Almost surely, 2^208561949 is an apocalyptic number.

It is an amenable number.

208561949 is a deficient number, since it is larger than the sum of its proper divisors (2857087).

208561949 is an equidigital number, since it uses as much as digits as its factorization.

208561949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2857086.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 208561949 is about 14441.6740373130. The cubic root of 208561949 is about 593.0323145545.

The spelling of 208561949 in words is "two hundred eight million, five hundred sixty-one thousand, nine hundred forty-nine".