21927047 has 4 divisors (see below), whose sum is σ = 21957936. Its totient is φ = 21896160.

The previous prime is 21927029. The next prime is 21927049. The reversal of 21927047 is 74072912.

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 21927047 - 2¹² = 21922951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21927049) 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, 14354 + ... + 15807.

It is an arithmetic number, because the mean of its divisors is an integer number (5489484).

Almost surely, 2^21927047 is an apocalyptic number.

21927047 is a deficient number, since it is larger than the sum of its proper divisors (30889).

21927047 is an equidigital number, since it uses as much as digits as its factorization.

21927047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30888.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 21927047 is about 4682.6324861129. The cubic root of 21927047 is about 279.8938670887.

Adding to 21927047 its reverse (74072912), we get a palindrome (95999959).

The spelling of 21927047 in words is "twenty-one million, nine hundred twenty-seven thousand, forty-seven".