21751404287 has 2 divisors, whose sum is σ = 21751404288. Its totient is φ = 21751404286.

The previous prime is 21751404263. The next prime is 21751404319. The reversal of 21751404287 is 78240415712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21751404287 - 2¹⁰ = 21751403263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21751404247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10875702143 + 10875702144.

It is an arithmetic number, because the mean of its divisors is an integer number (10875702144).

Almost surely, 2^21751404287 is an apocalyptic number.

21751404287 is a deficient number, since it is larger than the sum of its proper divisors (1).

21751404287 is an equidigital number, since it uses as much as digits as its factorization.

21751404287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 125440, while the sum is 41.

Adding to 21751404287 its reverse (78240415712), we get a palindrome (99991819999).

The spelling of 21751404287 in words is "twenty-one billion, seven hundred fifty-one million, four hundred four thousand, two hundred eighty-seven".