21443389 has 8 divisors (see below), whose sum is σ = 23431968. Its totient is φ = 19461360.

The previous prime is 21443363. The next prime is 21443431. The reversal of 21443389 is 98334412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21443389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21443329) 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, 7419 + ... + 9895.

It is an arithmetic number, because the mean of its divisors is an integer number (2928996).

Almost surely, 2^21443389 is an apocalyptic number.

It is an amenable number.

21443389 is a deficient number, since it is larger than the sum of its proper divisors (1988579).

21443389 is a wasteful number, since it uses less digits than its factorization.

21443389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3275.

The product of its digits is 20736, while the sum is 34.

The square root of 21443389 is about 4630.7007029174. The cubic root of 21443389 is about 277.8206190575.

The spelling of 21443389 in words is "twenty-one million, four hundred forty-three thousand, three hundred eighty-nine".