21389369 has 8 divisors (see below), whose sum is σ = 21866112. Its totient is φ = 20915440.

The previous prime is 21389363. The next prime is 21389377. The reversal of 21389369 is 96398312.

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

It is a cyclic number.

It is not a de Polignac number, because 21389369 - 2⁴ = 21389353 is a prime.

It is a super-2 number, since 2×21389369² = 915010212436322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21389363) 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, 23024 + ... + 23934.

It is an arithmetic number, because the mean of its divisors is an integer number (2733264).

Almost surely, 2^21389369 is an apocalyptic number.

It is an amenable number.

21389369 is a deficient number, since it is larger than the sum of its proper divisors (476743).

21389369 is an equidigital number, since it uses as much as digits as its factorization.

21389369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1407.

The product of its digits is 69984, while the sum is 41.

The square root of 21389369 is about 4624.8642142229. The cubic root of 21389369 is about 277.5871284453.

The spelling of 21389369 in words is "twenty-one million, three hundred eighty-nine thousand, three hundred sixty-nine".