21002841 has 32 divisors (see below), whose sum is σ = 33546240. Its totient is φ = 12949200.

The previous prime is 21002797. The next prime is 21002857. The reversal of 21002841 is 14820012.

It is not a de Polignac number, because 21002841 - 2⁶ = 21002777 is a prime.

It is a super-2 number, since 2×21002841² = 882238660142562, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21002881) 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 31 ways as a sum of consecutive naturals, for example, 18706 + ... + 19796.

It is an arithmetic number, because the mean of its divisors is an integer number (1048320).

Almost surely, 2^21002841 is an apocalyptic number.

It is an amenable number.

21002841 is a deficient number, since it is larger than the sum of its proper divisors (12543399).

21002841 is a wasteful number, since it uses less digits than its factorization.

21002841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1154 (or 1148 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 21002841 is about 4582.8856629857. The cubic root of 21002841 is about 275.9048585114.

Adding to 21002841 its reverse (14820012), we get a palindrome (35822853).

The spelling of 21002841 in words is "twenty-one million, two thousand, eight hundred forty-one".