16655981 has 4 divisors (see below), whose sum is σ = 16688352. Its totient is φ = 16623612.

The previous prime is 16655929. The next prime is 16655983. The reversal of 16655981 is 18955661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16655981 - 2⁶ = 16655917 is a prime.

It is a super-2 number, since 2×16655981² = 554843406144722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16655983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15401 + ... + 16446.

It is an arithmetic number, because the mean of its divisors is an integer number (4172088).

Almost surely, 2^16655981 is an apocalyptic number.

It is an amenable number.

16655981 is a deficient number, since it is larger than the sum of its proper divisors (32371).

16655981 is an equidigital number, since it uses as much as digits as its factorization.

16655981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32370.

The product of its digits is 64800, while the sum is 41.

The square root of 16655981 is about 4081.1739732582. The cubic root of 16655981 is about 255.3818756127.

The spelling of 16655981 in words is "sixteen million, six hundred fifty-five thousand, nine hundred eighty-one".