28431671820 has 96 divisors (see below), whose sum is σ = 84859622400. Its totient is φ = 7091794944.

The previous prime is 28431671819. The next prime is 28431671857. The reversal of 28431671820 is 2817613482.

It is a super-2 number, since 2×28431671820² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 67789 + ... + 247908.

It is an arithmetic number, because the mean of its divisors is an integer number (883954400).

Almost surely, 2^28431671820 is an apocalyptic number.

28431671820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28431671820 is an abundant number, since it is smaller than the sum of its proper divisors (56427950580).

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

28431671820 is a wasteful number, since it uses less digits than its factorization.

28431671820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315807 (or 315805 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 42.

The spelling of 28431671820 in words is "twenty-eight billion, four hundred thirty-one million, six hundred seventy-one thousand, eight hundred twenty".