28778408164 has 45 divisors (see below), whose sum is σ = 55477231705. Its totient is φ = 13062434000.

The previous prime is 28778408161. The next prime is 28778408173. The reversal of 28778408164 is 46180487782.

The square root of 28778408164 is 169642.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 24819481764 + 3958926400 = 157542^2 + 62920^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28778408161) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 41053014 + ... + 41053714.

Almost surely, 2^28778408164 is an apocalyptic number.

28778408164 is the 169642-nd square number.

It is an amenable number.

28778408164 is a deficient number, since it is larger than the sum of its proper divisors (26698823541).

28778408164 is an frugal number, since it uses more digits than its factorization.

28778408164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1450 (or 714 counting only the distinct ones).

The product of its (nonzero) digits is 4816896, while the sum is 55.

The spelling of 28778408164 in words is "twenty-eight billion, seven hundred seventy-eight million, four hundred eight thousand, one hundred sixty-four".