28979491778 has 8 divisors (see below), whose sum is σ = 43471696572. Its totient is φ = 14488926256.

The previous prime is 28979491699. The next prime is 28979491819. The reversal of 28979491778 is 87719497982.

It can be written as a sum of positive squares in 2 ways, for example, as 20147815249 + 8831676529 = 141943^2 + 93977^2 .

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

It is a super-2 number, since 2×28979491778² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 364625 + ... + 436932.

Almost surely, 2^28979491778 is an apocalyptic number.

28979491778 is a deficient number, since it is larger than the sum of its proper divisors (14492204794).

28979491778 is a wasteful number, since it uses less digits than its factorization.

28979491778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819636.

The product of its digits is 128024064, while the sum is 71.

The spelling of 28979491778 in words is "twenty-eight billion, nine hundred seventy-nine million, four hundred ninety-one thousand, seven hundred seventy-eight".