21254143 has 2 divisors, whose sum is σ = 21254144. Its totient is φ = 21254142.

The previous prime is 21254119. The next prime is 21254147. The reversal of 21254143 is 34145212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21254143 is a prime.

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

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21254147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627071 + 10627072.

It is an arithmetic number, because the mean of its divisors is an integer number (10627072).

Almost surely, 2^21254143 is an apocalyptic number.

21254143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21254143 is an equidigital number, since it uses as much as digits as its factorization.

21254143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 22.

The square root of 21254143 is about 4610.2215781891. The cubic root of 21254143 is about 277.0009122987. Note that the first 3 decimals are identical.

Adding to 21254143 its reverse (34145212), we get a palindrome (55399355).

The spelling of 21254143 in words is "twenty-one million, two hundred fifty-four thousand, one hundred forty-three".