21258327 has 4 divisors (see below), whose sum is σ = 28344440. Its totient is φ = 14172216.

The previous prime is 21258301. The next prime is 21258329. The reversal of 21258327 is 72385212.

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

It is not a de Polignac number, because 21258327 - 2⁷ = 21258199 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21258294 and 21258303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21258329) 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, 3543052 + ... + 3543057.

It is an arithmetic number, because the mean of its divisors is an integer number (7086110).

Almost surely, 2^21258327 is an apocalyptic number.

21258327 is a deficient number, since it is larger than the sum of its proper divisors (7086113).

21258327 is an equidigital number, since it uses as much as digits as its factorization.

21258327 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7086112.

The product of its digits is 6720, while the sum is 30.

The square root of 21258327 is about 4610.6753301442. The cubic root of 21258327 is about 277.0190875125.

The spelling of 21258327 in words is "twenty-one million, two hundred fifty-eight thousand, three hundred twenty-seven".