28431377856 has 84 divisors (see below), whose sum is σ = 93135340272. Its totient is φ = 8123249664.

The previous prime is 28431377839. The next prime is 28431377869. The reversal of 28431377856 is 65877313482.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (84).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3521685 + ... + 3529748.

Almost surely, 2^28431377856 is an apocalyptic number.

It is an amenable number.

28431377856 is an abundant number, since it is smaller than the sum of its proper divisors (64703962416).

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

28431377856 is a wasteful number, since it uses less digits than its factorization.

28431377856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7051458 (or 7051445 counting only the distinct ones).

The product of its digits is 6773760, while the sum is 54.

The spelling of 28431377856 in words is "twenty-eight billion, four hundred thirty-one million, three hundred seventy-seven thousand, eight hundred fifty-six".