21185241 has 16 divisors (see below), whose sum is σ = 35217408. Its totient is φ = 11005200.

The previous prime is 21185221. The next prime is 21185243. The reversal of 21185241 is 14258112.

It is not a de Polignac number, because 21185241 - 2⁷ = 21185113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21185243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45625 + ... + 46086.

It is an arithmetic number, because the mean of its divisors is an integer number (2201088).

Almost surely, 2^21185241 is an apocalyptic number.

21185241 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21185241 is a deficient number, since it is larger than the sum of its proper divisors (14032167).

21185241 is a wasteful number, since it uses less digits than its factorization.

21185241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91732.

The product of its digits is 640, while the sum is 24.

The square root of 21185241 is about 4602.7427692627. The cubic root of 21185241 is about 276.7012596864.

The spelling of 21185241 in words is "twenty-one million, one hundred eighty-five thousand, two hundred forty-one".