21234727 has 4 divisors (see below), whose sum is σ = 22158000. Its totient is φ = 20311456.

The previous prime is 21234713. The next prime is 21234767. The reversal of 21234727 is 72743212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21234727 is a prime.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21234695 and 21234704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21234767) 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, 461602 + ... + 461647.

It is an arithmetic number, because the mean of its divisors is an integer number (5539500).

Almost surely, 2^21234727 is an apocalyptic number.

21234727 is a deficient number, since it is larger than the sum of its proper divisors (923273).

21234727 is an equidigital number, since it uses as much as digits as its factorization.

21234727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923272.

The product of its digits is 4704, while the sum is 28.

The square root of 21234727 is about 4608.1153414384. The cubic root of 21234727 is about 276.9165383447.

Adding to 21234727 its reverse (72743212), we get a palindrome (93977939).

The spelling of 21234727 in words is "twenty-one million, two hundred thirty-four thousand, seven hundred twenty-seven".