21134857 has 2 divisors, whose sum is σ = 21134858. Its totient is φ = 21134856.

The previous prime is 21134843. The next prime is 21134899. The reversal of 21134857 is 75843112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21013056 + 121801 = 4584^2 + 349^2 .

It is a cyclic number.

It is not a de Polignac number, because 21134857 - 2¹⁵ = 21102089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21134837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10567428 + 10567429.

It is an arithmetic number, because the mean of its divisors is an integer number (10567429).

Almost surely, 2^21134857 is an apocalyptic number.

It is an amenable number.

21134857 is a deficient number, since it is larger than the sum of its proper divisors (1).

21134857 is an equidigital number, since it uses as much as digits as its factorization.

21134857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 31.

The square root of 21134857 is about 4597.2662528942. The cubic root of 21134857 is about 276.4817297643.

Adding to 21134857 its reverse (75843112), we get a palindrome (96977969).

The spelling of 21134857 in words is "twenty-one million, one hundred thirty-four thousand, eight hundred fifty-seven".