28778396946 has 48 divisors (see below), whose sum is σ = 63331492224. Its totient is φ = 8666437536.

The previous prime is 28778396929. The next prime is 28778396947. The reversal of 28778396946 is 64969387782.

It is a super-2 number, since 2×28778396946² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28778396947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 88791 + ... + 255813.

It is an arithmetic number, because the mean of its divisors is an integer number (1319406088).

Almost surely, 2^28778396946 is an apocalyptic number.

28778396946 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 28778396946, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31665746112).

28778396946 is an abundant number, since it is smaller than the sum of its proper divisors (34553095278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28778396946 is a wasteful number, since it uses less digits than its factorization.

28778396946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167135 (or 167088 counting only the distinct ones).

The product of its digits is 219469824, while the sum is 69.

The spelling of 28778396946 in words is "twenty-eight billion, seven hundred seventy-eight million, three hundred ninety-six thousand, nine hundred forty-six".