16487786981 has 2 divisors, whose sum is σ = 16487786982. Its totient is φ = 16487786980.

The previous prime is 16487786977. The next prime is 16487786983. The reversal of 16487786981 is 18968778461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13892393956 + 2595393025 = 117866^2 + 50945^2 .

It is a cyclic number.

It is not a de Polignac number, because 16487786981 - 2² = 16487786977 is a prime.

It is a super-2 number, since 2×16487786981² (a number of 21 digits) contains 22 as substring.

Together with 16487786983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16487786983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8243893490 + 8243893491.

It is an arithmetic number, because the mean of its divisors is an integer number (8243893491).

Almost surely, 2^16487786981 is an apocalyptic number.

It is an amenable number.

16487786981 is a deficient number, since it is larger than the sum of its proper divisors (1).

16487786981 is an equidigital number, since it uses as much as digits as its factorization.

16487786981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32514048, while the sum is 65.

The spelling of 16487786981 in words is "sixteen billion, four hundred eighty-seven million, seven hundred eighty-six thousand, nine hundred eighty-one".