28691324928 has 672 divisors, whose sum is σ = 103047759360. Its totient is φ = 7803371520.

The previous prime is 28691324923. The next prime is 28691324971. The reversal of 28691324928 is 82942319682.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×28691324928² (a number of 22 digits) contains 22 as substring.

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

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28691324923) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 404103133 + ... + 404103203.

It is an arithmetic number, because the mean of its divisors is an integer number (153344880).

Almost surely, 2^28691324928 is an apocalyptic number.

28691324928 is a gapful number since it is divisible by the number (28) 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 28691324928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51523879680).

28691324928 is an abundant number, since it is smaller than the sum of its proper divisors (74356434432).

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

28691324928 is an frugal number, since it uses more digits than its factorization.

28691324928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148 (or 112 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 54.

The spelling of 28691324928 in words is "twenty-eight billion, six hundred ninety-one million, three hundred twenty-four thousand, nine hundred twenty-eight".