21010020007 has 2 divisors, whose sum is σ = 21010020008. Its totient is φ = 21010020006.

The previous prime is 21010019999. The next prime is 21010020047. The reversal of 21010020007 is 70002001012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21010020007 - 2³ = 21010019999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010020047) 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, 10505010003 + 10505010004.

It is an arithmetic number, because the mean of its divisors is an integer number (10505010004).

Almost surely, 2^21010020007 is an apocalyptic number.

21010020007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010020007 is an equidigital number, since it uses as much as digits as its factorization.

21010020007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28, while the sum is 13.

Adding to 21010020007 its reverse (70002001012), we get a palindrome (91012021019).

The spelling of 21010020007 in words is "twenty-one billion, ten million, twenty thousand, seven".