16927981 has 12 divisors (see below), whose sum is σ = 20226108. Its totient is φ = 14116032.

The previous prime is 16927973. The next prime is 16927991. The reversal of 16927981 is 18972961.

It can be written as a sum of positive squares in 2 ways, for example, as 15642025 + 1285956 = 3955^2 + 1134^2 .

It is not a de Polignac number, because 16927981 - 2³ = 16927973 is a prime.

It is a super-2 number, since 2×16927981² = 573113081472722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16927961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2856 + ... + 6481.

It is an arithmetic number, because the mean of its divisors is an integer number (1685509).

Almost surely, 2^16927981 is an apocalyptic number.

It is an amenable number.

16927981 is a deficient number, since it is larger than the sum of its proper divisors (3298127).

16927981 is an equidigital number, since it uses as much as digits as its factorization.

16927981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9388 (or 9381 counting only the distinct ones).

The product of its digits is 54432, while the sum is 43.

The square root of 16927981 is about 4114.3627696157. The cubic root of 16927981 is about 256.7645448555.

The spelling of 16927981 in words is "sixteen million, nine hundred twenty-seven thousand, nine hundred eighty-one".