21210216017707 has 2 divisors, whose sum is σ = 21210216017708. Its totient is φ = 21210216017706.

The previous prime is 21210216017687. The next prime is 21210216017791. The reversal of 21210216017707 is 70771061201212.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21210216017707 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210216017797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605108008853 + 10605108008854.

It is an arithmetic number, because the mean of its divisors is an integer number (10605108008854).

Almost surely, 2^{21210216017707} is an apocalyptic number.

21210216017707 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210216017707 is an equidigital number, since it uses as much as digits as its factorization.

21210216017707 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16464, while the sum is 37.

Adding to 21210216017707 its reverse (70771061201212), we get a palindrome (91981277218919).

The spelling of 21210216017707 in words is "twenty-one trillion, two hundred ten billion, two hundred sixteen million, seventeen thousand, seven hundred seven".