16561474 has 4 divisors (see below), whose sum is σ = 24842214. Its totient is φ = 8280736.

The previous prime is 16561469. The next prime is 16561507. The reversal of 16561474 is 47416561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47416561 = 47 ⋅1008863.

It can be written as a sum of positive squares in only one way, i.e., 16524225 + 37249 = 4065^2 + 193^2 .

It is an alternating number because its digits alternate between odd and even.

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4140367 + ... + 4140370.

Almost surely, 2^16561474 is an apocalyptic number.

16561474 is a deficient number, since it is larger than the sum of its proper divisors (8280740).

16561474 is an equidigital number, since it uses as much as digits as its factorization.

16561474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8280739.

The product of its digits is 20160, while the sum is 34.

The square root of 16561474 is about 4069.5790937147. The cubic root of 16561474 is about 254.8979419861.

The spelling of 16561474 in words is "sixteen million, five hundred sixty-one thousand, four hundred seventy-four".