208406726057 has 4 divisors (see below), whose sum is σ = 208413182676. Its totient is φ = 208400269440.

The previous prime is 208406725997. The next prime is 208406726081. The reversal of 208406726057 is 750627604802.

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 102740121961 + 105666604096 = 320531^2 + 325064^2 .

It is a cyclic number.

It is not a de Polignac number, because 208406726057 - 2¹² = 208406721961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208406726357) 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, 3179648 + ... + 3244529.

It is an arithmetic number, because the mean of its divisors is an integer number (52103295669).

Almost surely, 2^208406726057 is an apocalyptic number.

It is an amenable number.

208406726057 is a deficient number, since it is larger than the sum of its proper divisors (6456619).

208406726057 is an equidigital number, since it uses as much as digits as its factorization.

208406726057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6456618.

The product of its (nonzero) digits is 1128960, while the sum is 47.

The spelling of 208406726057 in words is "two hundred eight billion, four hundred six million, seven hundred twenty-six thousand, fifty-seven".