21320343 has 24 divisors (see below), whose sum is σ = 34684416. Its totient is φ = 12502800.

The previous prime is 21320323. The next prime is 21320401. The reversal of 21320343 is 34302312.

21320343 is a `hidden beast` number, since 2 + 1 + 320 + 343 = 666.

It is not a de Polignac number, because 21320343 - 2⁵ = 21320311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320323) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 405 + ... + 6542.

It is an arithmetic number, because the mean of its divisors is an integer number (1445184).

Almost surely, 2^21320343 is an apocalyptic number.

21320343 is a deficient number, since it is larger than the sum of its proper divisors (13364073).

21320343 is a wasteful number, since it uses less digits than its factorization.

21320343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6995 (or 6992 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 21320343 is about 4617.3956945447. The cubic root of 21320343 is about 277.2882045973.

Adding to 21320343 its reverse (34302312), we get a palindrome (55622655).

The spelling of 21320343 in words is "twenty-one million, three hundred twenty thousand, three hundred forty-three".