21013220515097 has 2 divisors, whose sum is σ = 21013220515098. Its totient is φ = 21013220515096.

The previous prime is 21013220515087. The next prime is 21013220515163. The reversal of 21013220515097 is 79051502231012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18724910818441 + 2288309696656 = 4327229^2 + 1512716^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013220515097 - 2⁶ = 21013220515033 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21013220515097.

It is not a weakly prime, because it can be changed into another prime (21013220515037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506610257548 + 10506610257549.

It is an arithmetic number, because the mean of its divisors is an integer number (10506610257549).

Almost surely, 2^{21013220515097} is an apocalyptic number.

It is an amenable number.

21013220515097 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013220515097 is an equidigital number, since it uses as much as digits as its factorization.

21013220515097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 38.

The spelling of 21013220515097 in words is "twenty-one trillion, thirteen billion, two hundred twenty million, five hundred fifteen thousand, ninety-seven".