28261385792640 has 3840 divisors, whose sum is σ = 139285733811840. Its totient is φ = 5412334878720.

The previous prime is 28261385792639. The next prime is 28261385792669. The reversal of 28261385792640 is 4629758316282.

28261385792640 is a `hidden beast` number, since 2 + 8 + 2 + 6 + 1 + 38 + 579 + 26 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 43952388159 + ... + 43952388801.

It is a 1-persistent number, because it is pandigital, but 2⋅28261385792640 = 56522771585280 is not.

Almost surely, 2^{28261385792640} is an apocalyptic number.

28261385792640 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 28261385792640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69642866905920).

28261385792640 is an abundant number, since it is smaller than the sum of its proper divisors (111024348019200).

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

28261385792640 is a wasteful number, since it uses less digits than its factorization.

28261385792640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 734 (or 684 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 63.

The spelling of 28261385792640 in words is "twenty-eight trillion, two hundred sixty-one billion, three hundred eighty-five million, seven hundred ninety-two thousand, six hundred forty".