161874729 has 9 divisors (see below), whose sum is σ = 233874199. Its totient is φ = 107891040.

The previous prime is 161874719. The next prime is 161874733. The reversal of 161874729 is 927478161.

It is a happy number.

The square root of 161874729 is 12723.

It is a perfect power (a square), and thus also a powerful number.

161874729 is a `hidden beast` number, since 1 + 618 + 7 + 4 + 7 + 29 = 666.

It can be written as a sum of positive squares in only one way, i.e., 159441129 + 2433600 = 12627^2 + 1560^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 161874729 - 2¹¹ = 161872681 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161874709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 36049 + ... + 40289.

Almost surely, 2^161874729 is an apocalyptic number.

161874729 is the 12723-rd square number.

161874729 is the 6362-nd centered octagonal number.

It is an amenable number.

161874729 is a deficient number, since it is larger than the sum of its proper divisors (71999470).

161874729 is an frugal number, since it uses more digits than its factorization.

161874729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8488 (or 4244 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The cubic root of 161874729 is about 544.9956277179.

The spelling of 161874729 in words is "one hundred sixty-one million, eight hundred seventy-four thousand, seven hundred twenty-nine".