161183521 has 4 divisors (see below), whose sum is σ = 161277844. Its totient is φ = 161089200.

The previous prime is 161183509. The next prime is 161183527. The reversal of 161183521 is 125381161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125381161 = 3623 ⋅34607.

It can be written as a sum of positive squares in 2 ways, for example, as 8042896 + 153140625 = 2836^2 + 12375^2 .

It is a cyclic number.

It is not a de Polignac number, because 161183521 - 2¹⁵ = 161150753 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161183521.

It is not an unprimeable number, because it can be changed into a prime (161183527) 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, 44550 + ... + 48031.

It is an arithmetic number, because the mean of its divisors is an integer number (40319461).

Almost surely, 2^161183521 is an apocalyptic number.

It is an amenable number.

161183521 is a deficient number, since it is larger than the sum of its proper divisors (94323).

161183521 is an equidigital number, since it uses as much as digits as its factorization.

161183521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94322.

The product of its digits is 1440, while the sum is 28.

The square root of 161183521 is about 12695.8072212837. The cubic root of 161183521 is about 544.2188072814.

The spelling of 161183521 in words is "one hundred sixty-one million, one hundred eighty-three thousand, five hundred twenty-one".