21997067551213 has 2 divisors, whose sum is σ = 21997067551214. Its totient is φ = 21997067551212.

The previous prime is 21997067551183. The next prime is 21997067551231. The reversal of 21997067551213 is 31215576079912.

Together with next prime (21997067551231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17541329168169 + 4455738383044 = 4188237^2 + 2110862^2 .

It is a cyclic number.

It is not a de Polignac number, because 21997067551213 - 2⁹ = 21997067550701 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21997067551913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10998533775606 + 10998533775607.

It is an arithmetic number, because the mean of its divisors is an integer number (10998533775607).

Almost surely, 2^{21997067551213} is an apocalyptic number.

It is an amenable number.

21997067551213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21997067551213 is an equidigital number, since it uses as much as digits as its factorization.

21997067551213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7144200, while the sum is 58.

The spelling of 21997067551213 in words is "twenty-one trillion, nine hundred ninety-seven billion, sixty-seven million, five hundred fifty-one thousand, two hundred thirteen".