16561983 has 8 divisors (see below), whose sum is σ = 22176000. Its totient is φ = 10994648.

The previous prime is 16561981. The next prime is 16561999. The reversal of 16561983 is 38916561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16561983 - 2¹ = 16561981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10833 + ... + 12266.

It is an arithmetic number, because the mean of its divisors is an integer number (2772000).

Almost surely, 2^16561983 is an apocalyptic number.

16561983 is a deficient number, since it is larger than the sum of its proper divisors (5614017).

16561983 is a wasteful number, since it uses less digits than its factorization.

16561983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23341.

The product of its digits is 38880, while the sum is 39.

The square root of 16561983 is about 4069.6416304142. The cubic root of 16561983 is about 254.9005533021.

The spelling of 16561983 in words is "sixteen million, five hundred sixty-one thousand, nine hundred eighty-three".