28207750649 has 4 divisors (see below), whose sum is σ = 30377577636. Its totient is φ = 26037923664.

The previous prime is 28207750631. The next prime is 28207750657. The reversal of 28207750649 is 94605770282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94605770282 = 2 ⋅47302885141.

It can be written as a sum of positive squares in 2 ways, for example, as 2388081424 + 25819669225 = 48868^2 + 160685^2 .

It is a cyclic number.

It is not a de Polignac number, because 28207750649 - 2⁸ = 28207750393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28207750597 and 28207750606.

It is not an unprimeable number, because it can be changed into a prime (28207750619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1084913474 + ... + 1084913499.

It is an arithmetic number, because the mean of its divisors is an integer number (7594394409).

Almost surely, 2^28207750649 is an apocalyptic number.

It is an amenable number.

28207750649 is a deficient number, since it is larger than the sum of its proper divisors (2169826987).

28207750649 is a wasteful number, since it uses less digits than its factorization.

28207750649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2169826986.

The product of its (nonzero) digits is 1693440, while the sum is 50.

The spelling of 28207750649 in words is "twenty-eight billion, two hundred seven million, seven hundred fifty thousand, six hundred forty-nine".