16851785961613 has 2 divisors, whose sum is σ = 16851785961614. Its totient is φ = 16851785961612.

The previous prime is 16851785961587. The next prime is 16851785961631. The reversal of 16851785961613 is 31616958715861.

Together with next prime (16851785961631) 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., 14111840704329 + 2739945257284 = 3756573^2 + 1655278^2 .

It is a cyclic number.

It is not a de Polignac number, because 16851785961613 - 2¹⁷ = 16851785830541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16851785961113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8425892980806 + 8425892980807.

It is an arithmetic number, because the mean of its divisors is an integer number (8425892980807).

Almost surely, 2^{16851785961613} is an apocalyptic number.

It is an amenable number.

16851785961613 is a deficient number, since it is larger than the sum of its proper divisors (1).

16851785961613 is an equidigital number, since it uses as much as digits as its factorization.

16851785961613 is an evil number, because the sum of its binary digits is even.

The product of its digits is 65318400, while the sum is 67.

The spelling of 16851785961613 in words is "sixteen trillion, eight hundred fifty-one billion, seven hundred eighty-five million, nine hundred sixty-one thousand, six hundred thirteen".