21412 has 12 divisors (see below), whose sum is σ = 38556. Its totient is φ = 10400.

The previous prime is 21407. The next prime is 21419.

21412 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 18496 + 2916 = 136^2 + 54^2 .

It is a nude number because it is divisible by every one of its digits.

It is an alternating number because its digits alternate between even and odd.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (21419) by changing a digit.

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, 162 + ... + 262.

It is an arithmetic number, because the mean of its divisors is an integer number (3213).

2²¹⁴¹² is an apocalyptic number.

It is an amenable number.

21412 is a deficient number, since it is larger than the sum of its proper divisors (17144).

21412 is a wasteful number, since it uses less digits than its factorization.

21412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 156 counting only the distinct ones).

The product of its digits is 16, while the sum is 10.

The square root of 21412 is about 146.3283977907. The cubic root of 21412 is about 27.7684994197.

The spelling of 21412 in words is "twenty-one thousand, four hundred twelve", and thus it is an iban number.