21320927 has 4 divisors (see below), whose sum is σ = 21520296. Its totient is φ = 21121560.

The previous prime is 21320921. The next prime is 21320947. The reversal of 21320927 is 72902312.

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 21320927 - 2⁴ = 21320911 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21320896 and 21320905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320921) 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, 99524 + ... + 99737.

It is an arithmetic number, because the mean of its divisors is an integer number (5380074).

Almost surely, 2^21320927 is an apocalyptic number.

21320927 is a deficient number, since it is larger than the sum of its proper divisors (199369).

21320927 is a wasteful number, since it uses less digits than its factorization.

21320927 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199368.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 21320927 is about 4617.4589332229. The cubic root of 21320927 is about 277.2907363707.

The spelling of 21320927 in words is "twenty-one million, three hundred twenty thousand, nine hundred twenty-seven".