21036249 has 24 divisors (see below), whose sum is σ = 34448960. Its totient is φ = 12262752.

The previous prime is 21036241. The next prime is 21036269. The reversal of 21036249 is 94263012.

It is not a de Polignac number, because 21036249 - 2³ = 21036241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21036241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2509 + ... + 6954.

Almost surely, 2^21036249 is an apocalyptic number.

It is an amenable number.

21036249 is a deficient number, since it is larger than the sum of its proper divisors (13412711).

21036249 is a wasteful number, since it uses less digits than its factorization.

21036249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9501 (or 9498 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 21036249 is about 4586.5290798162. The cubic root of 21036249 is about 276.0510696298.

The spelling of 21036249 in words is "twenty-one million, thirty-six thousand, two hundred forty-nine".