21326071 has 4 divisors (see below), whose sum is σ = 22966552. Its totient is φ = 19685592.

The previous prime is 21326069. The next prime is 21326077. The reversal of 21326071 is 17062312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21326071 - 2¹ = 21326069 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 (21326077) 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, 820221 + ... + 820246.

It is an arithmetic number, because the mean of its divisors is an integer number (5741638).

Almost surely, 2^21326071 is an apocalyptic number.

21326071 is a deficient number, since it is larger than the sum of its proper divisors (1640481).

21326071 is a wasteful number, since it uses less digits than its factorization.

21326071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1640480.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 21326071 is about 4618.0159159535. The cubic root of 21326071 is about 277.3130347891.

Adding to 21326071 its reverse (17062312), we get a palindrome (38388383).

The spelling of 21326071 in words is "twenty-one million, three hundred twenty-six thousand, seventy-one".