28787779 has 8 divisors (see below), whose sum is σ = 29201120. Its totient is φ = 28377216.

The previous prime is 28787777. The next prime is 28787797. The reversal of 28787779 is 97778782.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28787779 - 2¹ = 28787777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28787771) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28027 + ... + 29035.

It is an arithmetic number, because the mean of its divisors is an integer number (3650140).

Almost surely, 2^28787779 is an apocalyptic number.

28787779 is a deficient number, since it is larger than the sum of its proper divisors (413341).

28787779 is a wasteful number, since it uses less digits than its factorization.

28787779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1389.

The product of its digits is 2765952, while the sum is 55.

The square root of 28787779 is about 5365.4244007348. The cubic root of 28787779 is about 306.4804100290.

The spelling of 28787779 in words is "twenty-eight million, seven hundred eighty-seven thousand, seven hundred seventy-nine".