21606071 has 8 divisors (see below), whose sum is σ = 21925344. Its totient is φ = 21288960.

The previous prime is 21606061. The next prime is 21606083. The reversal of 21606071 is 17060612.

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 21606071 - 2⁶ = 21606007 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 (21606061) 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, 33926 + ... + 34556.

It is an arithmetic number, because the mean of its divisors is an integer number (2740668).

Almost surely, 2^21606071 is an apocalyptic number.

21606071 is a deficient number, since it is larger than the sum of its proper divisors (319273).

21606071 is an equidigital number, since it uses as much as digits as its factorization.

21606071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 21606071 is about 4648.2331051702. The cubic root of 21606071 is about 278.5214193188.

Adding to 21606071 its reverse (17060612), we get a palindrome (38666683).

The spelling of 21606071 in words is "twenty-one million, six hundred six thousand, seventy-one".