21145241 has 8 divisors (see below), whose sum is σ = 23387784. Its totient is φ = 18990720.

The previous prime is 21145213. The next prime is 21145249. The reversal of 21145241 is 14254112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6864400 + 14280841 = 2620^2 + 3779^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21145241 - 2⁶ = 21145177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21145249) 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 7 ways as a sum of consecutive naturals, for example, 21500 + ... + 22461.

It is an arithmetic number, because the mean of its divisors is an integer number (2923473).

Almost surely, 2^21145241 is an apocalyptic number.

It is an amenable number.

21145241 is a deficient number, since it is larger than the sum of its proper divisors (2242543).

21145241 is a wasteful number, since it uses less digits than its factorization.

21145241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44011.

The product of its digits is 320, while the sum is 20.

The square root of 21145241 is about 4598.3954810347. The cubic root of 21145241 is about 276.5270027813.

Adding to 21145241 its reverse (14254112), we get a palindrome (35399353).

The spelling of 21145241 in words is "twenty-one million, one hundred forty-five thousand, two hundred forty-one".