21671071 has 8 divisors (see below), whose sum is σ = 21942000. Its totient is φ = 21402048.

The previous prime is 21671063. The next prime is 21671087. The reversal of 21671071 is 17017612.

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 21671071 - 2³ = 21671063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21671171) 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, 43180 + ... + 43678.

It is an arithmetic number, because the mean of its divisors is an integer number (2742750).

Almost surely, 2^21671071 is an apocalyptic number.

21671071 is a deficient number, since it is larger than the sum of its proper divisors (270929).

21671071 is a wasteful number, since it uses less digits than its factorization.

21671071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 953.

The product of its (nonzero) digits is 588, while the sum is 25.

The square root of 21671071 is about 4655.2197585076. The cubic root of 21671071 is about 278.8004422513.

Adding to 21671071 its reverse (17017612), we get a palindrome (38688683).

The spelling of 21671071 in words is "twenty-one million, six hundred seventy-one thousand, seventy-one".