28637773561 has 2 divisors, whose sum is σ = 28637773562. Its totient is φ = 28637773560.

The previous prime is 28637773559. The next prime is 28637773609. The reversal of 28637773561 is 16537773682.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27695283561 + 942490000 = 166419^2 + 30700^2 .

It is a cyclic number.

It is not a de Polignac number, because 28637773561 - 2¹ = 28637773559 is a prime.

It is a super-2 number, since 2×28637773561² (a number of 22 digits) contains 22 as substring.

Together with 28637773559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28637770561) 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, 14318886780 + 14318886781.

It is an arithmetic number, because the mean of its divisors is an integer number (14318886781).

Almost surely, 2^28637773561 is an apocalyptic number.

It is an amenable number.

28637773561 is a deficient number, since it is larger than the sum of its proper divisors (1).

28637773561 is an equidigital number, since it uses as much as digits as its factorization.

28637773561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8890560, while the sum is 55.

The spelling of 28637773561 in words is "twenty-eight billion, six hundred thirty-seven million, seven hundred seventy-three thousand, five hundred sixty-one".