21392927 has 4 divisors (see below), whose sum is σ = 21404496. Its totient is φ = 21381360.

The previous prime is 21392893. The next prime is 21392929. The reversal of 21392927 is 72929312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21392927 - 2⁶ = 21392863 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 (21392929) 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, 2318 + ... + 6939.

It is an arithmetic number, because the mean of its divisors is an integer number (5351124).

Almost surely, 2^21392927 is an apocalyptic number.

21392927 is a deficient number, since it is larger than the sum of its proper divisors (11569).

21392927 is an equidigital number, since it uses as much as digits as its factorization.

21392927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11568.

The product of its digits is 13608, while the sum is 35.

The square root of 21392927 is about 4625.2488581697. The cubic root of 21392927 is about 277.6025192725.

The spelling of 21392927 in words is "twenty-one million, three hundred ninety-two thousand, nine hundred twenty-seven".