28640366977 has 4 divisors (see below), whose sum is σ = 28759206916. Its totient is φ = 28521527040.

The previous prime is 28640366971. The next prime is 28640367011. The reversal of 28640366977 is 77966304682.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18089174016 + 10551192961 = 134496^2 + 102719^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28640366977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28640366971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59419608 + ... + 59420089.

It is an arithmetic number, because the mean of its divisors is an integer number (7189801729).

Almost surely, 2^28640366977 is an apocalyptic number.

It is an amenable number.

28640366977 is a deficient number, since it is larger than the sum of its proper divisors (118839939).

28640366977 is a wasteful number, since it uses less digits than its factorization.

28640366977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118839938.

The product of its (nonzero) digits is 18289152, while the sum is 58.

The spelling of 28640366977 in words is "twenty-eight billion, six hundred forty million, three hundred sixty-six thousand, nine hundred seventy-seven".