28399856784 has 80 divisors (see below), whose sum is σ = 80691002112. Its totient is φ = 8552484864.

The previous prime is 28399856777. The next prime is 28399856791. The reversal of 28399856784 is 48765899382.

It is an interprime number because it is at equal distance from previous prime (28399856777) and next prime (28399856791).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 454849 + ... + 513504.

Almost surely, 2^28399856784 is an apocalyptic number.

28399856784 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

28399856784 is an abundant number, since it is smaller than the sum of its proper divisors (52291145328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28399856784 is a wasteful number, since it uses less digits than its factorization.

28399856784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968424 (or 968418 counting only the distinct ones).

The product of its digits is 209018880, while the sum is 69.

The spelling of 28399856784 in words is "twenty-eight billion, three hundred ninety-nine million, eight hundred fifty-six thousand, seven hundred eighty-four".