28207645789 has 4 divisors (see below), whose sum is σ = 29180323260. Its totient is φ = 27234968320.

The previous prime is 28207645787. The next prime is 28207645793. The reversal of 28207645789 is 98754670282.

It is a happy number.

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 13987083289 + 14220562500 = 118267^2 + 119250^2 .

It is a cyclic number.

It is not a de Polignac number, because 28207645789 - 2¹ = 28207645787 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28207645787) 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, 486338692 + ... + 486338749.

It is an arithmetic number, because the mean of its divisors is an integer number (7295080815).

Almost surely, 2^28207645789 is an apocalyptic number.

28207645789 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28207645789 is a deficient number, since it is larger than the sum of its proper divisors (972677471).

28207645789 is an equidigital number, since it uses as much as digits as its factorization.

28207645789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 972677470.

The product of its (nonzero) digits is 13547520, while the sum is 58.

The spelling of 28207645789 in words is "twenty-eight billion, two hundred seven million, six hundred forty-five thousand, seven hundred eighty-nine".