161643457 has 2 divisors, whose sum is σ = 161643458. Its totient is φ = 161643456.

The previous prime is 161643439. The next prime is 161643467. The reversal of 161643457 is 754346161.

161643457 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152547201 + 9096256 = 12351^2 + 3016^2 .

It is an emirp because it is prime and its reverse (754346161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161643457 - 2¹⁵ = 161610689 is a prime.

It is a super-2 number, since 2×161643457² = 52257214381821698, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (161643467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80821728 + 80821729.

It is an arithmetic number, because the mean of its divisors is an integer number (80821729).

Almost surely, 2^161643457 is an apocalyptic number.

It is an amenable number.

161643457 is a deficient number, since it is larger than the sum of its proper divisors (1).

161643457 is an equidigital number, since it uses as much as digits as its factorization.

161643457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 37.

The square root of 161643457 is about 12713.9080144541. The cubic root of 161643457 is about 544.7359571624.

The spelling of 161643457 in words is "one hundred sixty-one million, six hundred forty-three thousand, four hundred fifty-seven".