28233121780 has 12 divisors (see below), whose sum is σ = 59289555780. Its totient is φ = 11293248704.

The previous prime is 28233121751. The next prime is 28233121781. The reversal of 28233121780 is 8712133282.

It can be written as a sum of positive squares in 2 ways, for example, as 7457358736 + 20775763044 = 86356^2 + 144138^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28233121781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 705828025 + ... + 705828064.

It is an arithmetic number, because the mean of its divisors is an integer number (4940796315).

Almost surely, 2^28233121780 is an apocalyptic number.

28233121780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28233121780 is an abundant number, since it is smaller than the sum of its proper divisors (31056434000).

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

28233121780 is a wasteful number, since it uses less digits than its factorization.

28233121780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1411656098 (or 1411656096 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The spelling of 28233121780 in words is "twenty-eight billion, two hundred thirty-three million, one hundred twenty-one thousand, seven hundred eighty".