16681986531 has 20 divisors (see below), whose sum is σ = 28480006192. Its totient is φ = 9532563408.

The previous prime is 16681986527. The next prime is 16681986533. The reversal of 16681986531 is 13568918661.

16681986531 is a `hidden beast` number, since 16 + 6 + 8 + 1 + 98 + 6 + 531 = 666.

It is not a de Polignac number, because 16681986531 - 2² = 16681986527 is a prime.

It is a super-2 number, since 2×16681986531² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16681986533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 14710180 + ... + 14711313.

Almost surely, 2^16681986531 is an apocalyptic number.

16681986531 is a deficient number, since it is larger than the sum of its proper divisors (11798019661).

16681986531 is an equidigital number, since it uses as much as digits as its factorization.

16681986531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29421512 (or 29421503 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The spelling of 16681986531 in words is "sixteen billion, six hundred eighty-one million, nine hundred eighty-six thousand, five hundred thirty-one".