21254143571 has 2 divisors, whose sum is σ = 21254143572. Its totient is φ = 21254143570.

The previous prime is 21254143567. The next prime is 21254143619. The reversal of 21254143571 is 17534145212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21254143571 - 2² = 21254143567 is a prime.

It is not a weakly prime, because it can be changed into another prime (21254143871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10627071785 + 10627071786.

It is an arithmetic number, because the mean of its divisors is an integer number (10627071786).

Almost surely, 2^21254143571 is an apocalyptic number.

21254143571 is a deficient number, since it is larger than the sum of its proper divisors (1).

21254143571 is an equidigital number, since it uses as much as digits as its factorization.

21254143571 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33600, while the sum is 35.

Adding to 21254143571 its reverse (17534145212), we get a palindrome (38788288783).

The spelling of 21254143571 in words is "twenty-one billion, two hundred fifty-four million, one hundred forty-three thousand, five hundred seventy-one".