28505953840 has 480 divisors, whose sum is σ = 89056800000. Its totient is φ = 8385140736.

The previous prime is 28505953823. The next prime is 28505953873. The reversal of 28505953840 is 4835950582.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 57125911 + ... + 57126409.

It is an arithmetic number, because the mean of its divisors is an integer number (185535000).

Almost surely, 2^28505953840 is an apocalyptic number.

28505953840 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 28505953840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44528400000).

28505953840 is an abundant number, since it is smaller than the sum of its proper divisors (60550846160).

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

28505953840 is a wasteful number, since it uses less digits than its factorization.

28505953840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 617 (or 604 counting only the distinct ones).

The product of its (nonzero) digits is 1728000, while the sum is 49.

The spelling of 28505953840 in words is "twenty-eight billion, five hundred five million, nine hundred fifty-three thousand, eight hundred forty".