28123261380 has 216 divisors, whose sum is σ = 88587547776. Its totient is φ = 7221502080.

The previous prime is 28123261379. The next prime is 28123261391. The reversal of 28123261380 is 8316232182.

28123261380 is a `hidden beast` number, since 2 + 8 + 1 + 2 + 32 + 613 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 63483439 + ... + 63483881.

It is an arithmetic number, because the mean of its divisors is an integer number (410127536).

Almost surely, 2^28123261380 is an apocalyptic number.

28123261380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28123261380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44293773888).

28123261380 is an abundant number, since it is smaller than the sum of its proper divisors (60464286396).

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

28123261380 is a wasteful number, since it uses less digits than its factorization.

28123261380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 887 (or 851 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 28123261380 in words is "twenty-eight billion, one hundred twenty-three million, two hundred sixty-one thousand, three hundred eighty".