21002102071 has 2 divisors, whose sum is σ = 21002102072. Its totient is φ = 21002102070.

The previous prime is 21002102063. The next prime is 21002102111. The reversal of 21002102071 is 17020120012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21002102071 - 2³ = 21002102063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002102021) 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, 10501051035 + 10501051036.

It is an arithmetic number, because the mean of its divisors is an integer number (10501051036).

Almost surely, 2^21002102071 is an apocalyptic number.

21002102071 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002102071 is an equidigital number, since it uses as much as digits as its factorization.

21002102071 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56, while the sum is 16.

Adding to 21002102071 its reverse (17020120012), we get a palindrome (38022222083).

The spelling of 21002102071 in words is "twenty-one billion, two million, one hundred two thousand, seventy-one".