28549497778 has 8 divisors (see below), whose sum is σ = 42983445420. Its totient is φ = 14221682640.

The previous prime is 28549497761. The next prime is 28549497841. The reversal of 28549497778 is 87779494582.

It can be written as a sum of positive squares in 2 ways, for example, as 28317148729 + 232349049 = 168277^2 + 15243^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26532453 + ... + 26533528.

Almost surely, 2^28549497778 is an apocalyptic number.

28549497778 is a deficient number, since it is larger than the sum of its proper divisors (14433947642).

28549497778 is a wasteful number, since it uses less digits than its factorization.

28549497778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53066252.

The product of its digits is 284497920, while the sum is 70.

The spelling of 28549497778 in words is "twenty-eight billion, five hundred forty-nine million, four hundred ninety-seven thousand, seven hundred seventy-eight".