21057327 has 10 divisors (see below), whose sum is σ = 31456128. Its totient is φ = 14038164.

The previous prime is 21057317. The next prime is 21057331. The reversal of 21057327 is 72375012.

It is not a de Polignac number, because 21057327 - 2⁷ = 21057199 is a prime.

It is a super-2 number, since 2×21057327² = 886822040769858, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 21057327.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21057307) 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 9 ways as a sum of consecutive naturals, for example, 129903 + ... + 130064.

Almost surely, 2^21057327 is an apocalyptic number.

21057327 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21057327 is a deficient number, since it is larger than the sum of its proper divisors (10398801).

21057327 is an equidigital number, since it uses as much as digits as its factorization.

21057327 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259979 (or 259970 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 27.

The square root of 21057327 is about 4588.8263205312. The cubic root of 21057327 is about 276.1432385037.

The spelling of 21057327 in words is "twenty-one million, fifty-seven thousand, three hundred twenty-seven".