21142133 has 4 divisors (see below), whose sum is σ = 21713580. Its totient is φ = 20570688.

The previous prime is 21142127. The next prime is 21142139. The reversal of 21142133 is 33124112.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21142127) and next prime (21142139).

It can be written as a sum of positive squares in 2 ways, for example, as 18852964 + 2289169 = 4342^2 + 1513^2 .

It is a cyclic number.

It is not a de Polignac number, because 21142133 - 2⁸ = 21141877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21142139) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 285668 + ... + 285741.

It is an arithmetic number, because the mean of its divisors is an integer number (5428395).

Almost surely, 2^21142133 is an apocalyptic number.

It is an amenable number.

21142133 is a deficient number, since it is larger than the sum of its proper divisors (571447).

21142133 is an equidigital number, since it uses as much as digits as its factorization.

21142133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571446.

The product of its digits is 144, while the sum is 17.

The square root of 21142133 is about 4598.0575246510. The cubic root of 21142133 is about 276.5134538218.

Adding to 21142133 its reverse (33124112), we get a palindrome (54266245).

The spelling of 21142133 in words is "twenty-one million, one hundred forty-two thousand, one hundred thirty-three".