28117923840 has 576 divisors, whose sum is σ = 104730706080. Its totient is φ = 6952058880.

The previous prime is 28117923817. The next prime is 28117923859. The reversal of 28117923840 is 4832971182.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (576).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 205240252 + ... + 205240388.

Almost surely, 2^28117923840 is an apocalyptic number.

28117923840 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 28117923840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52365353040).

28117923840 is an abundant number, since it is smaller than the sum of its proper divisors (76612782240).

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

28117923840 is a wasteful number, since it uses less digits than its factorization.

28117923840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 295 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The spelling of 28117923840 in words is "twenty-eight billion, one hundred seventeen million, nine hundred twenty-three thousand, eight hundred forty".