161405522 has 4 divisors (see below), whose sum is σ = 242108286. Its totient is φ = 80702760.

The previous prime is 161405521. The next prime is 161405527. The reversal of 161405522 is 225504161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 160300921 + 1104601 = 12661^2 + 1051^2 .

It is a junction number, because it is equal to n+sod(n) for n = 161405491 and 161405500.

It is not an unprimeable number, because it can be changed into a prime (161405521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40351379 + ... + 40351382.

Almost surely, 2^161405522 is an apocalyptic number.

161405522 is a deficient number, since it is larger than the sum of its proper divisors (80702764).

161405522 is an equidigital number, since it uses as much as digits as its factorization.

161405522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80702763.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 161405522 is about 12704.5472961456. The cubic root of 161405522 is about 544.4685468189.

Adding to 161405522 its reverse (225504161), we get a palindrome (386909683).

The spelling of 161405522 in words is "one hundred sixty-one million, four hundred five thousand, five hundred twenty-two".