21135849 has 8 divisors (see below), whose sum is σ = 32207040. Its totient is φ = 12077616.

The previous prime is 21135841. The next prime is 21135857. The reversal of 21135849 is 94853112.

It is an interprime number because it is at equal distance from previous prime (21135841) and next prime (21135857).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21135849 - 2³ = 21135841 is a prime.

It is a super-2 number, since 2×21135849² = 893448225901602, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21135841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 503214 + ... + 503255.

It is an arithmetic number, because the mean of its divisors is an integer number (4025880).

Almost surely, 2^21135849 is an apocalyptic number.

It is an amenable number.

21135849 is a deficient number, since it is larger than the sum of its proper divisors (11071191).

21135849 is a wasteful number, since it uses less digits than its factorization.

21135849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1006479.

The product of its digits is 8640, while the sum is 33.

The square root of 21135849 is about 4597.3741418336. The cubic root of 21135849 is about 276.4860554080.

The spelling of 21135849 in words is "twenty-one million, one hundred thirty-five thousand, eight hundred forty-nine".