209018890 has 8 divisors (see below), whose sum is σ = 376234020. Its totient is φ = 83607552.

The previous prime is 209018869. The next prime is 209018891. The reversal of 209018890 is 98810902.

It can be written as a sum of positive squares in 2 ways, for example, as 208831401 + 187489 = 14451^2 + 433^2 .

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

It is not an unprimeable number, because it can be changed into a prime (209018891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10450935 + ... + 10450954.

Almost surely, 2^209018890 is an apocalyptic number.

209018890 is a deficient number, since it is larger than the sum of its proper divisors (167215130).

209018890 is a wasteful number, since it uses less digits than its factorization.

209018890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20901896.

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 209018890 is about 14457.4856043504. The cubic root of 209018890 is about 593.4650926367.

It can be divided in two parts, 20901 and 8890, that added together give a cube (29791 = 31³).

The spelling of 209018890 in words is "two hundred nine million, eighteen thousand, eight hundred ninety".