28188086869 has 8 divisors (see below), whose sum is σ = 30141718488. Its totient is φ = 26267289600.

The previous prime is 28188086827. The next prime is 28188086879. The reversal of 28188086869 is 96868088182.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18242013969 + 9946072900 = 135063^2 + 99730^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28188086869 - 2¹⁹ = 28187562581 is a prime.

It is a super-2 number, since 2×28188086869² (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 28188086869.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28188086879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8206812 + ... + 8210245.

It is an arithmetic number, because the mean of its divisors is an integer number (3767714811).

Almost surely, 2^28188086869 is an apocalyptic number.

It is an amenable number.

28188086869 is a deficient number, since it is larger than the sum of its proper divisors (1953631619).

28188086869 is a wasteful number, since it uses less digits than its factorization.

28188086869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16417175.

The product of its (nonzero) digits is 21233664, while the sum is 64.

The spelling of 28188086869 in words is "twenty-eight billion, one hundred eighty-eight million, eighty-six thousand, eight hundred sixty-nine".