28187799720 has 32 divisors (see below), whose sum is σ = 84563399520. Its totient is φ = 7516746560.

The previous prime is 28187799713. The next prime is 28187799737. The reversal of 28187799720 is 2799778182.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117449046 + ... + 117449285.

It is an arithmetic number, because the mean of its divisors is an integer number (2642606235).

Almost surely, 2^28187799720 is an apocalyptic number.

28187799720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28187799720 is an abundant number, since it is smaller than the sum of its proper divisors (56375599800).

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

28187799720 is a wasteful number, since it uses less digits than its factorization.

28187799720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234898345 (or 234898341 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 60.

The spelling of 28187799720 in words is "twenty-eight billion, one hundred eighty-seven million, seven hundred ninety-nine thousand, seven hundred twenty".