21453427 has 2 divisors, whose sum is σ = 21453428. Its totient is φ = 21453426.

The previous prime is 21453401. The next prime is 21453433. The reversal of 21453427 is 72435412.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21453427 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21453395 and 21453404.

It is not a weakly prime, because it can be changed into another prime (21453727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10726713 + 10726714.

It is an arithmetic number, because the mean of its divisors is an integer number (10726714).

Almost surely, 2^21453427 is an apocalyptic number.

21453427 is a deficient number, since it is larger than the sum of its proper divisors (1).

21453427 is an equidigital number, since it uses as much as digits as its factorization.

21453427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 28.

The square root of 21453427 is about 4631.7844293533. The cubic root of 21453427 is about 277.8639630820.

Adding to 21453427 its reverse (72435412), we get a palindrome (93888839).

The spelling of 21453427 in words is "twenty-one million, four hundred fifty-three thousand, four hundred twenty-seven".