21361727 has 2 divisors, whose sum is σ = 21361728. Its totient is φ = 21361726.

The previous prime is 21361721. The next prime is 21361729. The reversal of 21361727 is 72716312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21361727 is a prime.

Together with 21361729, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21361727.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21361721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10680863 + 10680864.

It is an arithmetic number, because the mean of its divisors is an integer number (10680864).

Almost surely, 2^21361727 is an apocalyptic number.

21361727 is a deficient number, since it is larger than the sum of its proper divisors (1).

21361727 is an equidigital number, since it uses as much as digits as its factorization.

21361727 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3528, while the sum is 29.

The square root of 21361727 is about 4621.8748360379. The cubic root of 21361727 is about 277.4674993725.

The spelling of 21361727 in words is "twenty-one million, three hundred sixty-one thousand, seven hundred twenty-seven".