208420729 has 4 divisors (see below), whose sum is σ = 227368080. Its totient is φ = 189473380.

The previous prime is 208420721. The next prime is 208420757. The reversal of 208420729 is 927024802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 208420729 - 2³ = 208420721 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 208420694 and 208420703.

It is not an unprimeable number, because it can be changed into a prime (208420721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9473659 + ... + 9473680.

It is an arithmetic number, because the mean of its divisors is an integer number (56842020).

Almost surely, 2^208420729 is an apocalyptic number.

It is an amenable number.

208420729 is a deficient number, since it is larger than the sum of its proper divisors (18947351).

208420729 is a wasteful number, since it uses less digits than its factorization.

208420729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18947350.

The product of its (nonzero) digits is 16128, while the sum is 34.

The square root of 208420729 is about 14436.7838870020. The cubic root of 208420729 is about 592.8984343760.

The spelling of 208420729 in words is "two hundred eight million, four hundred twenty thousand, seven hundred twenty-nine".