16861637691443 has 2 divisors, whose sum is σ = 16861637691444. Its totient is φ = 16861637691442.

The previous prime is 16861637691341. The next prime is 16861637691463. The reversal of 16861637691443 is 34419673616861.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16861637691443 - 2¹⁰ = 16861637690419 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16861637691443.

It is not a weakly prime, because it can be changed into another prime (16861637691463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8430818845721 + 8430818845722.

It is an arithmetic number, because the mean of its divisors is an integer number (8430818845722).

Almost surely, 2^{16861637691443} is an apocalyptic number.

16861637691443 is a deficient number, since it is larger than the sum of its proper divisors (1).

16861637691443 is an equidigital number, since it uses as much as digits as its factorization.

16861637691443 is an evil number, because the sum of its binary digits is even.

The product of its digits is 94058496, while the sum is 65.

The spelling of 16861637691443 in words is "sixteen trillion, eight hundred sixty-one billion, six hundred thirty-seven million, six hundred ninety-one thousand, four hundred forty-three".