21144135 has 16 divisors (see below), whose sum is σ = 33976800. Its totient is φ = 11228160.

The previous prime is 21144121. The next prime is 21144173. The reversal of 21144135 is 53144112.

It is not a de Polignac number, because 21144135 - 2⁴ = 21144119 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 691 + ... + 6539.

It is an arithmetic number, because the mean of its divisors is an integer number (2123550).

Almost surely, 2^21144135 is an apocalyptic number.

21144135 is a deficient number, since it is larger than the sum of its proper divisors (12832665).

21144135 is a wasteful number, since it uses less digits than its factorization.

21144135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6098.

The product of its digits is 480, while the sum is 21.

The square root of 21144135 is about 4598.2752201233. The cubic root of 21144135 is about 276.5221814569.

Adding to 21144135 its reverse (53144112), we get a palindrome (74288247).

The spelling of 21144135 in words is "twenty-one million, one hundred forty-four thousand, one hundred thirty-five".