21021021000247 has 2 divisors, whose sum is σ = 21021021000248. Its totient is φ = 21021021000246.

The previous prime is 21021021000229. The next prime is 21021021000253. The reversal of 21021021000247 is 74200012012012.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021021000247 is a prime.

It is a super-2 number, since 2×21021021000247² (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 (21021021000047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510510500123 + 10510510500124.

It is an arithmetic number, because the mean of its divisors is an integer number (10510510500124).

Almost surely, 2^{21021021000247} is an apocalyptic number.

21021021000247 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021021000247 is an equidigital number, since it uses as much as digits as its factorization.

21021021000247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 22.

Adding to 21021021000247 its reverse (74200012012012), we get a palindrome (95221033012259).

The spelling of 21021021000247 in words is "twenty-one trillion, twenty-one billion, twenty-one million, two hundred forty-seven", and thus it is an aban number.