21075241 has 4 divisors (see below), whose sum is σ = 22991184. Its totient is φ = 19159300.

The previous prime is 21075239. The next prime is 21075247. The reversal of 21075241 is 14257012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21075241 - 2¹ = 21075239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21075247) 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, 957955 + ... + 957976.

It is an arithmetic number, because the mean of its divisors is an integer number (5747796).

Almost surely, 2^21075241 is an apocalyptic number.

It is an amenable number.

21075241 is a deficient number, since it is larger than the sum of its proper divisors (1915943).

21075241 is a wasteful number, since it uses less digits than its factorization.

21075241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1915942.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21075241 is about 4590.7778208055. Note that the first 3 decimals coincide. The cubic root of 21075241 is about 276.2215236510.

It can be divided in two parts, 21075 and 241, that added together give a square (21316 = 146²).

The spelling of 21075241 in words is "twenty-one million, seventy-five thousand, two hundred forty-one".