21388343 has 8 divisors (see below), whose sum is σ = 22009968. Its totient is φ = 20775744.

The previous prime is 21388333. The next prime is 21388373. The reversal of 21388343 is 34388312.

It is a happy number.

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 21388343 - 2⁴ = 21388327 is a prime.

It is a super-2 number, since 2×21388343² = 914922432571298, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21388313) 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, 2705 + ... + 7077.

It is an arithmetic number, because the mean of its divisors is an integer number (2751246).

Almost surely, 2^21388343 is an apocalyptic number.

21388343 is a deficient number, since it is larger than the sum of its proper divisors (621625).

21388343 is an equidigital number, since it uses as much as digits as its factorization.

21388343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4513.

The product of its digits is 13824, while the sum is 32.

The square root of 21388343 is about 4624.7532907172. The cubic root of 21388343 is about 277.5826899639.

The spelling of 21388343 in words is "twenty-one million, three hundred eighty-eight thousand, three hundred forty-three".