16841981 has 12 divisors (see below), whose sum is σ = 18468156. Its totient is φ = 15267840.

The previous prime is 16841977. The next prime is 16841987. The reversal of 16841981 is 18914861.

It can be written as a sum of positive squares in 2 ways, for example, as 10666756 + 6175225 = 3266^2 + 2485^2 .

It is not a de Polignac number, because 16841981 - 2² = 16841977 is a prime.

It is a super-2 number, since 2×16841981² = 567304648008722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16841987) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65405 + ... + 65661.

It is an arithmetic number, because the mean of its divisors is an integer number (1539013).

Almost surely, 2^16841981 is an apocalyptic number.

It is an amenable number.

16841981 is a deficient number, since it is larger than the sum of its proper divisors (1626175).

16841981 is an equidigital number, since it uses as much as digits as its factorization.

16841981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412 (or 341 counting only the distinct ones).

The product of its digits is 13824, while the sum is 38.

The square root of 16841981 is about 4103.8982687196. The cubic root of 16841981 is about 256.3289888557.

The spelling of 16841981 in words is "sixteen million, eight hundred forty-one thousand, nine hundred eighty-one".