21006961207 has 2 divisors, whose sum is σ = 21006961208. Its totient is φ = 21006961206.

The previous prime is 21006961201. The next prime is 21006961249. The reversal of 21006961207 is 70216960012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21006961207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21006961201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10503480603 + 10503480604.

It is an arithmetic number, because the mean of its divisors is an integer number (10503480604).

Almost surely, 2^21006961207 is an apocalyptic number.

21006961207 is a deficient number, since it is larger than the sum of its proper divisors (1).

21006961207 is an equidigital number, since it uses as much as digits as its factorization.

21006961207 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 34.

The spelling of 21006961207 in words is "twenty-one billion, six million, nine hundred sixty-one thousand, two hundred seven".