21449137 has 2 divisors, whose sum is σ = 21449138. Its totient is φ = 21449136.

The previous prime is 21449123. The next prime is 21449143. The reversal of 21449137 is 73194412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20802721 + 646416 = 4561^2 + 804^2 .

It is a cyclic number.

It is not a de Polignac number, because 21449137 - 2²³ = 13060529 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21449099 and 21449108.

It is not a weakly prime, because it can be changed into another prime (21449107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10724568 + 10724569.

It is an arithmetic number, because the mean of its divisors is an integer number (10724569).

Almost surely, 2^21449137 is an apocalyptic number.

It is an amenable number.

21449137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21449137 is an equidigital number, since it uses as much as digits as its factorization.

21449137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6048, while the sum is 31.

The square root of 21449137 is about 4631.3213017453. The cubic root of 21449137 is about 277.8454405421.

The spelling of 21449137 in words is "twenty-one million, four hundred forty-nine thousand, one hundred thirty-seven".