21134237 has 2 divisors, whose sum is σ = 21134238. Its totient is φ = 21134236.

The previous prime is 21134231. The next prime is 21134249. The reversal of 21134237 is 73243112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17799961 + 3334276 = 4219^2 + 1826^2 .

It is a cyclic number.

It is not a de Polignac number, because 21134237 - 2⁴ = 21134221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21134231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10567118 + 10567119.

It is an arithmetic number, because the mean of its divisors is an integer number (10567119).

Almost surely, 2^21134237 is an apocalyptic number.

It is an amenable number.

21134237 is a deficient number, since it is larger than the sum of its proper divisors (1).

21134237 is an equidigital number, since it uses as much as digits as its factorization.

21134237 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 23.

The square root of 21134237 is about 4597.1988210213. The cubic root of 21134237 is about 276.4790261682.

Adding to 21134237 its reverse (73243112), we get a palindrome (94377349).

The spelling of 21134237 in words is "twenty-one million, one hundred thirty-four thousand, two hundred thirty-seven".