16043981 has 2 divisors, whose sum is σ = 16043982. Its totient is φ = 16043980.

The previous prime is 16043953. The next prime is 16044011. The reversal of 16043981 is 18934061.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15642025 + 401956 = 3955^2 + 634^2 .

It is a cyclic number.

It is not a de Polignac number, because 16043981 - 2⁶ = 16043917 is a prime.

It is a super-2 number, since 2×16043981² = 514818652656722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16043921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8021990 + 8021991.

It is an arithmetic number, because the mean of its divisors is an integer number (8021991).

Almost surely, 2^16043981 is an apocalyptic number.

It is an amenable number.

16043981 is a deficient number, since it is larger than the sum of its proper divisors (1).

16043981 is an equidigital number, since it uses as much as digits as its factorization.

16043981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 16043981 is about 4005.4938521985. The cubic root of 16043981 is about 252.2148845296.

The spelling of 16043981 in words is "sixteen million, forty-three thousand, nine hundred eighty-one".