21645327 has 12 divisors (see below), whose sum is σ = 31723160. Its totient is φ = 13118160.

The previous prime is 21645319. The next prime is 21645331. The reversal of 21645327 is 72354612.

It is not a de Polignac number, because 21645327 - 2³ = 21645319 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21645294 and 21645303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21645307) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 29452 + ... + 30177.

Almost surely, 2^21645327 is an apocalyptic number.

21645327 is a deficient number, since it is larger than the sum of its proper divisors (10077833).

21645327 is a wasteful number, since it uses less digits than its factorization.

21645327 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59654 (or 59643 counting only the distinct ones).

The product of its digits is 10080, while the sum is 30.

The square root of 21645327 is about 4652.4538686590. The cubic root of 21645327 is about 278.6899988159.

Adding to 21645327 its reverse (72354612), we get a palindrome (93999939).

The spelling of 21645327 in words is "twenty-one million, six hundred forty-five thousand, three hundred twenty-seven".