21004334343247 has 2 divisors, whose sum is σ = 21004334343248. Its totient is φ = 21004334343246.

The previous prime is 21004334343203. The next prime is 21004334343259. The reversal of 21004334343247 is 74234343340012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21004334343247 is a prime.

It is a super-2 number, since 2×21004334343247² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21004334343547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502167171623 + 10502167171624.

It is an arithmetic number, because the mean of its divisors is an integer number (10502167171624).

Almost surely, 2^{21004334343247} is an apocalyptic number.

21004334343247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004334343247 is an equidigital number, since it uses as much as digits as its factorization.

21004334343247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 580608, while the sum is 40.

Adding to 21004334343247 its reverse (74234343340012), we get a palindrome (95238677683259).

The spelling of 21004334343247 in words is "twenty-one trillion, four billion, three hundred thirty-four million, three hundred forty-three thousand, two hundred forty-seven".