161857747 has 2 divisors, whose sum is σ = 161857748. Its totient is φ = 161857746.

The previous prime is 161857733. The next prime is 161857753. The reversal of 161857747 is 747758161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161857747 - 2¹⁵ = 161824979 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 161857697 and 161857706.

It is not a weakly prime, because it can be changed into another prime (161857757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80928873 + 80928874.

It is an arithmetic number, because the mean of its divisors is an integer number (80928874).

Almost surely, 2^161857747 is an apocalyptic number.

161857747 is a deficient number, since it is larger than the sum of its proper divisors (1).

161857747 is an equidigital number, since it uses as much as digits as its factorization.

161857747 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 329280, while the sum is 46.

The square root of 161857747 is about 12722.3326084488. The cubic root of 161857747 is about 544.9765688661.

It can be divided in two parts, 16185 and 7747, that added together give a palindrome (23932).

The spelling of 161857747 in words is "one hundred sixty-one million, eight hundred fifty-seven thousand, seven hundred forty-seven".