16581982 has 4 divisors (see below), whose sum is σ = 24872976. Its totient is φ = 8290990.

The previous prime is 16581977. The next prime is 16582001. The reversal of 16581982 is 28918561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 28918561 = 7 ⋅4131223.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4145494 + ... + 4145497.

It is an arithmetic number, because the mean of its divisors is an integer number (6218244).

Almost surely, 2^16581982 is an apocalyptic number.

16581982 is a deficient number, since it is larger than the sum of its proper divisors (8290994).

16581982 is an equidigital number, since it uses as much as digits as its factorization.

16581982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8290993.

The product of its digits is 34560, while the sum is 40.

The square root of 16581982 is about 4072.0979850686. The cubic root of 16581982 is about 255.0031115858.

The spelling of 16581982 in words is "sixteen million, five hundred eighty-one thousand, nine hundred eighty-two".