21085841 has 8 divisors (see below), whose sum is σ = 24220800. Its totient is φ = 17981568.

The previous prime is 21085837. The next prime is 21085847. The reversal of 21085841 is 14858012.

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 21085841 - 2² = 21085837 is a prime.

It is a super-2 number, since 2×21085841² = 889225381354562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21085847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6176 + ... + 8961.

It is an arithmetic number, because the mean of its divisors is an integer number (3027600).

Almost surely, 2^21085841 is an apocalyptic number.

It is an amenable number.

21085841 is a deficient number, since it is larger than the sum of its proper divisors (3134959).

21085841 is a wasteful number, since it uses less digits than its factorization.

21085841 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15343.

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 21085841 is about 4591.9321641331. The cubic root of 21085841 is about 276.2678253344.

The spelling of 21085841 in words is "twenty-one million, eighty-five thousand, eight hundred forty-one".