28177754981 has 2 divisors, whose sum is σ = 28177754982. Its totient is φ = 28177754980.

The previous prime is 28177754971. The next prime is 28177754993. The reversal of 28177754981 is 18945777182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20487341956 + 7690413025 = 143134^2 + 87695^2 .

It is a cyclic number.

It is not a de Polignac number, because 28177754981 - 2¹⁰ = 28177753957 is a prime.

It is a super-2 number, since 2×28177754981² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28177754981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28177754911) 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 as a sum of consecutive naturals, namely, 14088877490 + 14088877491.

It is an arithmetic number, because the mean of its divisors is an integer number (14088877491).

Almost surely, 2^28177754981 is an apocalyptic number.

It is an amenable number.

28177754981 is a deficient number, since it is larger than the sum of its proper divisors (1).

28177754981 is an equidigital number, since it uses as much as digits as its factorization.

28177754981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7902720, while the sum is 59.

The spelling of 28177754981 in words is "twenty-eight billion, one hundred seventy-seven million, seven hundred fifty-four thousand, nine hundred eighty-one".