16661172537439 has 2 divisors, whose sum is σ = 16661172537440. Its totient is φ = 16661172537438.

The previous prime is 16661172537343. The next prime is 16661172537467. The reversal of 16661172537439 is 93473527116661.

It is a strong prime.

It is an emirp because it is prime and its reverse (93473527116661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16661172537439 - 2²⁵ = 16661138983007 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16661172537539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330586268719 + 8330586268720.

It is an arithmetic number, because the mean of its divisors is an integer number (8330586268720).

Almost surely, 2^{16661172537439} is an apocalyptic number.

16661172537439 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661172537439 is an equidigital number, since it uses as much as digits as its factorization.

16661172537439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34292160, while the sum is 61.

The spelling of 16661172537439 in words is "sixteen trillion, six hundred sixty-one billion, one hundred seventy-two million, five hundred thirty-seven thousand, four hundred thirty-nine".