161204437 has 4 divisors (see below), whose sum is σ = 161803980. Its totient is φ = 160604896.

The previous prime is 161204423. The next prime is 161204443. The reversal of 161204437 is 734402161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 734402161 = 13477 ⋅54493.

It can be written as a sum of positive squares in 2 ways, for example, as 30536676 + 130667761 = 5526^2 + 11431^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161204437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161204137) 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, 299368 + ... + 299905.

It is an arithmetic number, because the mean of its divisors is an integer number (40450995).

Almost surely, 2^161204437 is an apocalyptic number.

It is an amenable number.

161204437 is a deficient number, since it is larger than the sum of its proper divisors (599543).

161204437 is an equidigital number, since it uses as much as digits as its factorization.

161204437 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599542.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 161204437 is about 12696.6309310777. The cubic root of 161204437 is about 544.2423464707.

Adding to 161204437 its reverse (734402161), we get a palindrome (895606598).

The spelling of 161204437 in words is "one hundred sixty-one million, two hundred four thousand, four hundred thirty-seven".