21498656 has 36 divisors (see below), whose sum is σ = 43278102. Its totient is φ = 10512384.

The previous prime is 21498649. The next prime is 21498679. The reversal of 21498656 is 65689412.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 20106256 + 1392400 = 4484^2 + 1180^2 .

It is a congruent number.

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 in 5 ways as a sum of consecutive naturals, for example, 111296 + ... + 111488.

Almost surely, 2^21498656 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 21498656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21639051).

21498656 is an abundant number, since it is smaller than the sum of its proper divisors (21779446).

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

21498656 is an equidigital number, since it uses as much as digits as its factorization.

21498656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321 (or 254 counting only the distinct ones).

The product of its digits is 103680, while the sum is 41.

The square root of 21498656 is about 4636.6643182357. The cubic root of 21498656 is about 278.0590941090.

The spelling of 21498656 in words is "twenty-one million, four hundred ninety-eight thousand, six hundred fifty-six".