28390000640 has 192 divisors, whose sum is σ = 73474128000. Its totient is φ = 10492968960.

The previous prime is 28390000579. The next prime is 28390000703. The reversal of 28390000640 is 4600009382.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 28390000597 and 28390000606.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7975181 + ... + 7978739.

It is an arithmetic number, because the mean of its divisors is an integer number (382677750).

Almost surely, 2^28390000640 is an apocalyptic number.

28390000640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

28390000640 is the 97280-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28390000640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36737064000).

28390000640 is an abundant number, since it is smaller than the sum of its proper divisors (45084127360).

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

28390000640 is a wasteful number, since it uses less digits than its factorization.

28390000640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3646 (or 3626 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The spelling of 28390000640 in words is "twenty-eight billion, three hundred ninety million, six hundred forty", and thus it is an aban number.