209121896 has 16 divisors (see below), whose sum is σ = 415168740. Its totient is φ = 98410240.

The previous prime is 209121851. The next prime is 209121917. The reversal of 209121896 is 698121902.

It can be written as a sum of positive squares in 2 ways, for example, as 207648100 + 1473796 = 14410^2 + 1214^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 768695 + ... + 768966.

Almost surely, 2^209121896 is an apocalyptic number.

It is an amenable number.

209121896 is a deficient number, since it is larger than the sum of its proper divisors (206046844).

209121896 is a wasteful number, since it uses less digits than its factorization.

209121896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537684 (or 1537680 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 209121896 is about 14461.0475415856. The cubic root of 209121896 is about 593.5625645705.

The spelling of 209121896 in words is "two hundred nine million, one hundred twenty-one thousand, eight hundred ninety-six".