21128927 has 8 divisors (see below), whose sum is σ = 22464864. Its totient is φ = 19827808.

The previous prime is 21128923. The next prime is 21128941. The reversal of 21128927 is 72982112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21128927 - 2² = 21128923 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21128893 and 21128902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21128923) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7448 + ... + 9885.

It is an arithmetic number, because the mean of its divisors is an integer number (2808108).

Almost surely, 2^21128927 is an apocalyptic number.

21128927 is a deficient number, since it is larger than the sum of its proper divisors (1335937).

21128927 is a wasteful number, since it uses less digits than its factorization.

21128927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17409.

The product of its digits is 4032, while the sum is 32.

The square root of 21128927 is about 4596.6212591424. The cubic root of 21128927 is about 276.4558690102.

The spelling of 21128927 in words is "twenty-one million, one hundred twenty-eight thousand, nine hundred twenty-seven".