21395727 has 24 divisors (see below), whose sum is σ = 33048288. Its totient is φ = 13305600.

The previous prime is 21395723. The next prime is 21395747. The reversal of 21395727 is 72759312.

It is not a de Polignac number, because 21395727 - 2² = 21395723 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21395691 and 21395700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21395723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7227 + ... + 9747.

It is an arithmetic number, because the mean of its divisors is an integer number (1377012).

Almost surely, 2^21395727 is an apocalyptic number.

21395727 is a deficient number, since it is larger than the sum of its proper divisors (11652561).

21395727 is a wasteful number, since it uses less digits than its factorization.

21395727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2591 (or 2588 counting only the distinct ones).

The product of its digits is 26460, while the sum is 36.

The square root of 21395727 is about 4625.5515346821. The cubic root of 21395727 is about 277.6146300221.

It can be divided in two parts, 21395 and 727, that added together give a palindrome (22122).

The spelling of 21395727 in words is "twenty-one million, three hundred ninety-five thousand, seven hundred twenty-seven".