28646906687981 has 2 divisors, whose sum is σ = 28646906687982. Its totient is φ = 28646906687980.

The previous prime is 28646906687957. The next prime is 28646906688007. The reversal of 28646906687981 is 18978660964682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28551389222500 + 95517465481 = 5343350^2 + 309059^2 .

It is a cyclic number.

It is not a de Polignac number, because 28646906687981 - 2²⁶ = 28646839579117 is a prime.

It is a super-2 number, since 2×28646906687981² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28646906687896 and 28646906687905.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28646906689981) 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, 14323453343990 + 14323453343991.

It is an arithmetic number, because the mean of its divisors is an integer number (14323453343991).

Almost surely, 2^{28646906687981} is an apocalyptic number.

It is an amenable number.

28646906687981 is a deficient number, since it is larger than the sum of its proper divisors (1).

28646906687981 is an equidigital number, since it uses as much as digits as its factorization.

28646906687981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3009871872, while the sum is 80.

The spelling of 28646906687981 in words is "twenty-eight trillion, six hundred forty-six billion, nine hundred six million, six hundred eighty-seven thousand, nine hundred eighty-one".