21864135 has 16 divisors (see below), whose sum is σ = 35042400. Its totient is φ = 11640960.

The previous prime is 21864121. The next prime is 21864187. The reversal of 21864135 is 53146812.

It is not a de Polignac number, because 21864135 - 2⁵ = 21864103 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, 13341 + ... + 14889.

It is an arithmetic number, because the mean of its divisors is an integer number (2190150).

Almost surely, 2^21864135 is an apocalyptic number.

21864135 is a deficient number, since it is larger than the sum of its proper divisors (13178265).

21864135 is a wasteful number, since it uses less digits than its factorization.

21864135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2498.

The product of its digits is 5760, while the sum is 30.

The square root of 21864135 is about 4675.9100718470. The cubic root of 21864135 is about 279.6259247842.

The spelling of 21864135 in words is "twenty-one million, eight hundred sixty-four thousand, one hundred thirty-five".