208220090 has 64 divisors (see below), whose sum is σ = 420922656. Its totient is φ = 73654272.

The previous prime is 208220071. The next prime is 208220101. The reversal of 208220090 is 90022802.

It can be written as a sum of positive squares in 16 ways, for example, as 38725729 + 169494361 = 6223^2 + 13019^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 350834 + ... + 351426.

Almost surely, 2^208220090 is an apocalyptic number.

208220090 is an abundant number, since it is smaller than the sum of its proper divisors (212702566).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

208220090 is a wasteful number, since it uses less digits than its factorization.

208220090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 208220090 is about 14429.8333323708. The cubic root of 208220090 is about 592.7081194262.

Adding to 208220090 its reverse (90022802), we get a palindrome (298242892).

The spelling of 208220090 in words is "two hundred eight million, two hundred twenty thousand, ninety".