28781775799 has 4 divisors (see below), whose sum is σ = 32893458064. Its totient is φ = 24670093536.

The previous prime is 28781775797. The next prime is 28781775809. The reversal of 28781775799 is 99757718782.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28781775799 - 2¹ = 28781775797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28781775793) 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, 2055841122 + ... + 2055841135.

It is an arithmetic number, because the mean of its divisors is an integer number (8223364516).

Almost surely, 2^28781775799 is an apocalyptic number.

28781775799 is a deficient number, since it is larger than the sum of its proper divisors (4111682265).

28781775799 is an equidigital number, since it uses as much as digits as its factorization.

28781775799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4111682264.

The product of its digits is 124467840, while the sum is 70.

The spelling of 28781775799 in words is "twenty-eight billion, seven hundred eighty-one million, seven hundred seventy-five thousand, seven hundred ninety-nine".