21998346 has 16 divisors (see below), whose sum is σ = 44080608. Its totient is φ = 7318800.

The previous prime is 21998341. The next prime is 21998359. The reversal of 21998346 is 64389912.

It is a junction number, because it is equal to n+sod(n) for n = 21998298 and 21998307.

It is not an unprimeable number, because it can be changed into a prime (21998341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 216 + ... + 6636.

It is an arithmetic number, because the mean of its divisors is an integer number (2755038).

Almost surely, 2^21998346 is an apocalyptic number.

21998346 is an abundant number, since it is smaller than the sum of its proper divisors (22082262).

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

21998346 is a wasteful number, since it uses less digits than its factorization.

21998346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6997.

The product of its digits is 93312, while the sum is 42.

The square root of 21998346 is about 4690.2394395169. The cubic root of 21998346 is about 280.1969108092.

The spelling of 21998346 in words is "twenty-one million, nine hundred ninety-eight thousand, three hundred forty-six".