21998344 has 32 divisors (see below), whose sum is σ = 43027200. Its totient is φ = 10532160.

The previous prime is 21998341. The next prime is 21998359. The reversal of 21998344 is 44389912.

It is a junction number, because it is equal to n+sod(n) for n = 21998297 and 21998306.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26122 + ... + 26950.

It is an arithmetic number, because the mean of its divisors is an integer number (1344600).

Almost surely, 2^21998344 is an apocalyptic number.

It is an amenable number.

21998344 is a deficient number, since it is larger than the sum of its proper divisors (21028856).

21998344 is a wasteful number, since it uses less digits than its factorization.

21998344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 973 (or 969 counting only the distinct ones).

The product of its digits is 62208, while the sum is 40.

The square root of 21998344 is about 4690.2392263082. The cubic root of 21998344 is about 280.1969023177.

The spelling of 21998344 in words is "twenty-one million, nine hundred ninety-eight thousand, three hundred forty-four".