21436927 has 2 divisors, whose sum is σ = 21436928. Its totient is φ = 21436926.

The previous prime is 21436873. The next prime is 21436931. The reversal of 21436927 is 72963412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21436927 - 2⁷ = 21436799 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21436892 and 21436901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21436957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10718463 + 10718464.

It is an arithmetic number, because the mean of its divisors is an integer number (10718464).

Almost surely, 2^21436927 is an apocalyptic number.

21436927 is a deficient number, since it is larger than the sum of its proper divisors (1).

21436927 is an equidigital number, since it uses as much as digits as its factorization.

21436927 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 34.

The square root of 21436927 is about 4630.0029157658. The cubic root of 21436927 is about 277.7927090226.

The spelling of 21436927 in words is "twenty-one million, four hundred thirty-six thousand, nine hundred twenty-seven".