21149 has 2 divisors, whose sum is σ = 21150. Its totient is φ = 21148.

The previous prime is 21143. The next prime is 21157. The reversal of 21149 is 94112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13924 + 7225 = 118^2 + 85^2 .

It is a cyclic number.

It is not a de Polignac number, because 21149 - 2¹² = 17053 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 21149.

It is not a weakly prime, because it can be changed into another prime (21143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10574 + 10575.

It is an arithmetic number, because the mean of its divisors is an integer number (10575).

2²¹¹⁴⁹ is an apocalyptic number.

It is an amenable number.

21149 is a deficient number, since it is larger than the sum of its proper divisors (1).

21149 is an equidigital number, since it uses as much as digits as its factorization.

21149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72, while the sum is 17.

The square root of 21149 is about 145.4269576110. The cubic root of 21149 is about 27.6543387925.

The spelling of 21149 in words is "twenty-one thousand, one hundred forty-nine".