20990208 has 72 divisors (see below), whose sum is σ = 56545216. Its totient is φ = 6912000.

The previous prime is 20990183. The next prime is 20990209. The reversal of 20990208 is 80209902.

It is not an unprimeable number, because it can be changed into a prime (20990209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115878 + ... + 116058.

Almost surely, 2^20990208 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20990208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28272608).

20990208 is an abundant number, since it is smaller than the sum of its proper divisors (35555008).

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

20990208 is a wasteful number, since it uses less digits than its factorization.

20990208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351 (or 337 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 20990208 is about 4581.5071755919. The cubic root of 20990208 is about 275.8495294070.

The spelling of 20990208 in words is "twenty million, nine hundred ninety thousand, two hundred eight".