208870661 has 8 divisors (see below), whose sum is σ = 214848504. Its totient is φ = 202910400.

The previous prime is 208870657. The next prime is 208870663. The reversal of 208870661 is 166078802.

It can be written as a sum of positive squares in 4 ways, for example, as 141729025 + 67141636 = 11905^2 + 8194^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 208870661 - 2² = 208870657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208870663) 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 7 ways as a sum of consecutive naturals, for example, 21911 + ... + 29963.

It is an arithmetic number, because the mean of its divisors is an integer number (26856063).

Almost surely, 2^208870661 is an apocalyptic number.

It is an amenable number.

208870661 is a deficient number, since it is larger than the sum of its proper divisors (5977843).

208870661 is an equidigital number, since it uses as much as digits as its factorization.

208870661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8791.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 208870661 is about 14452.3583196653. The cubic root of 208870661 is about 593.3247711245.

The spelling of 208870661 in words is "two hundred eight million, eight hundred seventy thousand, six hundred sixty-one".