28931696640 has 1152 divisors, whose sum is σ = 130503260160. Its totient is φ = 5971968000.

The previous prime is 28931696609. The next prime is 28931696641. The reversal of 28931696640 is 4669613982.

28931696640 is a `hidden beast` number, since 289 + 316 + 9 + 6 + 6 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (28931696641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 191600565 + ... + 191600715.

It is an arithmetic number, because the mean of its divisors is an integer number (113284080).

Almost surely, 2^28931696640 is an apocalyptic number.

28931696640 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 28931696640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65251630080).

28931696640 is an abundant number, since it is smaller than the sum of its proper divisors (101571563520).

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

28931696640 is a wasteful number, since it uses less digits than its factorization.

28931696640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 54.

The spelling of 28931696640 in words is "twenty-eight billion, nine hundred thirty-one million, six hundred ninety-six thousand, six hundred forty".