28128201100 has 36 divisors (see below), whose sum is σ = 61263488608. Its totient is φ = 11209752000.

The previous prime is 28128201053. The next prime is 28128201107. The reversal of 28128201100 is 110282182.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (28128201107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 491871 + ... + 546070.

Almost surely, 2^28128201100 is an apocalyptic number.

28128201100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28128201100 is an abundant number, since it is smaller than the sum of its proper divisors (33135287508).

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

28128201100 is a wasteful number, since it uses less digits than its factorization.

28128201100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1038226 (or 1038219 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 25.

Adding to 28128201100 its reverse (110282182), we get a palindrome (28238483282).

The spelling of 28128201100 in words is "twenty-eight billion, one hundred twenty-eight million, two hundred one thousand, one hundred".