21442135 has 16 divisors (see below), whose sum is σ = 30229920. Its totient is φ = 14394240.

The previous prime is 21442133. The next prime is 21442159. The reversal of 21442135 is 53124412.

It is not a de Polignac number, because 21442135 - 2¹ = 21442133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14280 + ... + 15709.

It is an arithmetic number, because the mean of its divisors is an integer number (1889370).

Almost surely, 2^21442135 is an apocalyptic number.

21442135 is a deficient number, since it is larger than the sum of its proper divisors (8787785).

21442135 is a wasteful number, since it uses less digits than its factorization.

21442135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30018.

The product of its digits is 960, while the sum is 22.

The square root of 21442135 is about 4630.5653002630. The cubic root of 21442135 is about 277.8152033425.

Adding to 21442135 its reverse (53124412), we get a palindrome (74566547).

The spelling of 21442135 in words is "twenty-one million, four hundred forty-two thousand, one hundred thirty-five".