28779355813 has 6 divisors (see below), whose sum is σ = 30993811142. Its totient is φ = 26564994600.

The previous prime is 28779355747. The next prime is 28779355819. The reversal of 28779355813 is 31855397782.

It can be written as a sum of positive squares in only one way, i.e., 19924169409 + 8855186404 = 141153^2 + 94102^2 .

It is not a de Polignac number, because 28779355813 - 2¹³ = 28779347621 is a prime.

It is a super-2 number, since 2×28779355813² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28779355819) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 588138 + ... + 635188.

Almost surely, 2^28779355813 is an apocalyptic number.

It is an amenable number.

28779355813 is a deficient number, since it is larger than the sum of its proper divisors (2214455329).

28779355813 is an frugal number, since it uses more digits than its factorization.

28779355813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94115 (or 47064 counting only the distinct ones).

The product of its digits is 12700800, while the sum is 58.

The spelling of 28779355813 in words is "twenty-eight billion, seven hundred seventy-nine million, three hundred fifty-five thousand, eight hundred thirteen".