21550730347 has 2 divisors, whose sum is σ = 21550730348. Its totient is φ = 21550730346.

The previous prime is 21550730339. The next prime is 21550730437. The reversal of 21550730347 is 74303705512.

Together with next prime (21550730437) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21550730347 - 2³ = 21550730339 is a prime.

It is not a weakly prime, because it can be changed into another prime (21550730317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10775365173 + 10775365174.

It is an arithmetic number, because the mean of its divisors is an integer number (10775365174).

Almost surely, 2^21550730347 is an apocalyptic number.

21550730347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21550730347 is an equidigital number, since it uses as much as digits as its factorization.

21550730347 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 88200, while the sum is 37.

The spelling of 21550730347 in words is "twenty-one billion, five hundred fifty million, seven hundred thirty thousand, three hundred forty-seven".