21346 has 8 divisors (see below), whose sum is σ = 34524. Its totient is φ = 9840.

The previous prime is 21341. The next prime is 21347. The reversal of 21346 is 64312.

It can be written as a sum of positive squares in 2 ways, for example, as 19321 + 2025 = 139^2 + 45^2 .

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

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (21341) by changing a digit.

21346 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 385 + ... + 436.

2²¹³⁴⁶ is an apocalyptic number.

21346 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21346 is a deficient number, since it is larger than the sum of its proper divisors (13178).

21346 is a wasteful number, since it uses less digits than its factorization.

21346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836.

The product of its digits is 144, while the sum is 16.

The square root of 21346 is about 146.1027036026. The cubic root of 21346 is about 27.7399389981.

Adding to 21346 its reverse (64312), we get a palindrome (85658).

The spelling of 21346 in words is "twenty-one thousand, three hundred forty-six".