20998288 has 10 divisors (see below), whose sum is σ = 40684214. Its totient is φ = 10499136.

The previous prime is 20998267. The next prime is 20998297. The reversal of 20998288 is 88289902.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15745024 + 5253264 = 3968^2 + 2292^2 .

It is a super-3 number, since 3×20998288³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656181 + ... + 656212.

Almost surely, 2^20998288 is an apocalyptic number.

It is an amenable number.

20998288 is a deficient number, since it is larger than the sum of its proper divisors (19685926).

20998288 is a wasteful number, since it uses less digits than its factorization.

20998288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1312401 (or 1312395 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 46.

The square root of 20998288 is about 4582.3888966346. The cubic root of 20998288 is about 275.8849201674.

The spelling of 20998288 in words is "twenty million, nine hundred ninety-eight thousand, two hundred eighty-eight".