161243673457 has 2 divisors, whose sum is σ = 161243673458. Its totient is φ = 161243673456.

The previous prime is 161243673377. The next prime is 161243673491. The reversal of 161243673457 is 754376342161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161243205601 + 467856 = 401551^2 + 684^2 .

It is a cyclic number.

It is not a de Polignac number, because 161243673457 - 2²³ = 161235284849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161243673457.

It is not a weakly prime, because it can be changed into another prime (161243674457) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80621836728 + 80621836729.

It is an arithmetic number, because the mean of its divisors is an integer number (80621836729).

Almost surely, 2^161243673457 is an apocalyptic number.

It is an amenable number.

161243673457 is a deficient number, since it is larger than the sum of its proper divisors (1).

161243673457 is an equidigital number, since it uses as much as digits as its factorization.

161243673457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2540160, while the sum is 49.

The spelling of 161243673457 in words is "one hundred sixty-one billion, two hundred forty-three million, six hundred seventy-three thousand, four hundred fifty-seven".