28139722380 has 960 divisors, whose sum is σ = 119899422720. Its totient is φ = 5346777600.

The previous prime is 28139722357. The next prime is 28139722381. The reversal of 28139722380 is 8322793182.

28139722380 is a `hidden beast` number, since 28 + 1 + 397 + 2 + 238 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (28139722381) by changing a digit.

It is a polite number, since it can be written in 319 ways as a sum of consecutive naturals, for example, 73471669 + ... + 73472051.

It is an arithmetic number, because the mean of its divisors is an integer number (124895232).

Almost surely, 2^28139722380 is an apocalyptic number.

28139722380 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 28139722380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59949711360).

28139722380 is an abundant number, since it is smaller than the sum of its proper divisors (91759700340).

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

28139722380 is a wasteful number, since it uses less digits than its factorization.

28139722380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 461 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 28139722380 in words is "twenty-eight billion, one hundred thirty-nine million, seven hundred twenty-two thousand, three hundred eighty".