28379778165 has 128 divisors (see below), whose sum is σ = 55729766400. Its totient is φ = 13646880000.

The previous prime is 28379778157. The next prime is 28379778169. The reversal of 28379778165 is 56187797382.

It is not a de Polignac number, because 28379778165 - 2³ = 28379778157 is a prime.

It is a super-2 number, since 2×28379778165² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28379778169) 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 127 ways as a sum of consecutive naturals, for example, 4847490 + ... + 4853340.

It is an arithmetic number, because the mean of its divisors is an integer number (435388800).

Almost surely, 2^28379778165 is an apocalyptic number.

It is an amenable number.

28379778165 is a deficient number, since it is larger than the sum of its proper divisors (27349988235).

28379778165 is a wasteful number, since it uses less digits than its factorization.

28379778165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5976 (or 5970 counting only the distinct ones).

The product of its digits is 35562240, while the sum is 63.

The spelling of 28379778165 in words is "twenty-eight billion, three hundred seventy-nine million, seven hundred seventy-eight thousand, one hundred sixty-five".