21775241 has 4 divisors (see below), whose sum is σ = 22238592. Its totient is φ = 21311892.

The previous prime is 21775219. The next prime is 21775261. The reversal of 21775241 is 14257712.

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 a de Polignac number, because none of the positive numbers 2^k-21775241 is a prime.

It is a super-2 number, since 2×21775241² = 948322241216162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21775261) 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, 231605 + ... + 231698.

It is an arithmetic number, because the mean of its divisors is an integer number (5559648).

Almost surely, 2^21775241 is an apocalyptic number.

It is an amenable number.

21775241 is a deficient number, since it is larger than the sum of its proper divisors (463351).

21775241 is an equidigital number, since it uses as much as digits as its factorization.

21775241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 463350.

The product of its digits is 3920, while the sum is 29.

The square root of 21775241 is about 4666.3948611321. The cubic root of 21775241 is about 279.2464474536.

The spelling of 21775241 in words is "twenty-one million, seven hundred seventy-five thousand, two hundred forty-one".