21250135 has 4 divisors (see below), whose sum is σ = 25500168. Its totient is φ = 17000104.

The previous prime is 21250133. The next prime is 21250139. The reversal of 21250135 is 53105212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21250135 - 2¹ = 21250133 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250133) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2125009 + ... + 2125018.

It is an arithmetic number, because the mean of its divisors is an integer number (6375042).

Almost surely, 2^21250135 is an apocalyptic number.

21250135 is a deficient number, since it is larger than the sum of its proper divisors (4250033).

21250135 is an equidigital number, since it uses as much as digits as its factorization.

21250135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4250032.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 21250135 is about 4609.7868714291. The cubic root of 21250135 is about 276.9834993885.

Adding to 21250135 its reverse (53105212), we get a palindrome (74355347).

The spelling of 21250135 in words is "twenty-one million, two hundred fifty thousand, one hundred thirty-five".