161587418 has 4 divisors (see below), whose sum is σ = 242381130. Its totient is φ = 80793708.

The previous prime is 161587411. The next prime is 161587423. The reversal of 161587418 is 814785161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 814785161 = 4241 ⋅192121.

It can be written as a sum of positive squares in only one way, i.e., 88604569 + 72982849 = 9413^2 + 8543^2 .

It is a super-2 number, since 2×161587418² = 52220987311813448, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (161587411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40396853 + ... + 40396856.

Almost surely, 2^161587418 is an apocalyptic number.

161587418 is a deficient number, since it is larger than the sum of its proper divisors (80793712).

161587418 is an equidigital number, since it uses as much as digits as its factorization.

161587418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80793711.

The product of its digits is 53760, while the sum is 41.

The square root of 161587418 is about 12711.7039770441. The cubic root of 161587418 is about 544.6729996978.

The spelling of 161587418 in words is "one hundred sixty-one million, five hundred eighty-seven thousand, four hundred eighteen".