21630227 has 4 divisors (see below), whose sum is σ = 22768680. Its totient is φ = 20491776.

The previous prime is 21630223. The next prime is 21630229. The reversal of 21630227 is 72203612.

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

It is a cyclic number.

It is not a de Polignac number, because 21630227 - 2² = 21630223 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21630223) 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, 569198 + ... + 569235.

It is an arithmetic number, because the mean of its divisors is an integer number (5692170).

Almost surely, 2^21630227 is an apocalyptic number.

21630227 is a deficient number, since it is larger than the sum of its proper divisors (1138453).

21630227 is a wasteful number, since it uses less digits than its factorization.

21630227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1138452.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 21630227 is about 4650.8307859994. The cubic root of 21630227 is about 278.6251780822.

Adding to 21630227 its reverse (72203612), we get a palindrome (93833839).

The spelling of 21630227 in words is "twenty-one million, six hundred thirty thousand, two hundred twenty-seven".