16143981 has 32 divisors (see below), whose sum is σ = 26016000. Its totient is φ = 8890560.

The previous prime is 16143979. The next prime is 16143991. The reversal of 16143981 is 18934161.

It is not a de Polignac number, because 16143981 - 2¹ = 16143979 is a prime.

It is a super-2 number, since 2×16143981² = 521256245056722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16143961) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29571 + ... + 30111.

It is an arithmetic number, because the mean of its divisors is an integer number (813000).

Almost surely, 2^16143981 is an apocalyptic number.

It is an amenable number.

16143981 is a deficient number, since it is larger than the sum of its proper divisors (9872019).

16143981 is an equidigital number, since it uses as much as digits as its factorization.

16143981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 594 (or 580 counting only the distinct ones).

The product of its digits is 5184, while the sum is 33.

The square root of 16143981 is about 4017.9573168465. The cubic root of 16143981 is about 252.7378068729.

The spelling of 16143981 in words is "sixteen million, one hundred forty-three thousand, nine hundred eighty-one".