21257327 has 36 divisors (see below), whose sum is σ = 28539216. Its totient is φ = 15724800.

The previous prime is 21257323. The next prime is 21257347. The reversal of 21257327 is 72375212.

It is not a de Polignac number, because 21257327 - 2² = 21257323 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21257327.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21257323) 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 35 ways as a sum of consecutive naturals, for example, 140702 + ... + 140852.

It is an arithmetic number, because the mean of its divisors is an integer number (792756).

Almost surely, 2^21257327 is an apocalyptic number.

21257327 is a deficient number, since it is larger than the sum of its proper divisors (7281889).

21257327 is a wasteful number, since it uses less digits than its factorization.

21257327 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 188 counting only the distinct ones).

The product of its digits is 5880, while the sum is 29.

The square root of 21257327 is about 4610.5668848852. The cubic root of 21257327 is about 277.0147437490.

The spelling of 21257327 in words is "twenty-one million, two hundred fifty-seven thousand, three hundred twenty-seven".