21171041 has 4 divisors (see below), whose sum is σ = 21332784. Its totient is φ = 21009300.

The previous prime is 21171037. The next prime is 21171043. The reversal of 21171041 is 14017112.

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 21171041 - 2² = 21171037 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21171043) 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, 80675 + ... + 80936.

It is an arithmetic number, because the mean of its divisors is an integer number (5333196).

Almost surely, 2^21171041 is an apocalyptic number.

It is an amenable number.

21171041 is a deficient number, since it is larger than the sum of its proper divisors (161743).

21171041 is a wasteful number, since it uses less digits than its factorization.

21171041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161742.

The product of its (nonzero) digits is 56, while the sum is 17.

The square root of 21171041 is about 4601.1999521864. The cubic root of 21171041 is about 276.6394236171.

Adding to 21171041 its reverse (14017112), we get a palindrome (35188153).

The spelling of 21171041 in words is "twenty-one million, one hundred seventy-one thousand, forty-one".