161234321 has 4 divisors (see below), whose sum is σ = 164276532. Its totient is φ = 158192112.

The previous prime is 161234309. The next prime is 161234329. The reversal of 161234321 is 123432161.

161234321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 123432161 = 1039 ⋅118799.

It can be written as a sum of positive squares in 2 ways, for example, as 136632721 + 24601600 = 11689^2 + 4960^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161234321 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 (161234329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1521026 + ... + 1521131.

It is an arithmetic number, because the mean of its divisors is an integer number (41069133).

Almost surely, 2^161234321 is an apocalyptic number.

It is an amenable number.

161234321 is a deficient number, since it is larger than the sum of its proper divisors (3042211).

161234321 is an equidigital number, since it uses as much as digits as its factorization.

161234321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3042210.

The product of its digits is 864, while the sum is 23.

The square root of 161234321 is about 12697.8077241703. The cubic root of 161234321 is about 544.2759748531.

Adding to 161234321 its reverse (123432161), we get a palindrome (284666482).

It can be divided in two parts, 16 and 1234321, that multiplied together give a square (19749136 = 4444²).

The spelling of 161234321 in words is "one hundred sixty-one million, two hundred thirty-four thousand, three hundred twenty-one".