28707720 has 32 divisors (see below), whose sum is σ = 86123520. Its totient is φ = 7655360.

The previous prime is 28707677. The next prime is 28707737. The reversal of 28707720 is 2770782.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119496 + ... + 119735.

It is an arithmetic number, because the mean of its divisors is an integer number (2691360).

Almost surely, 2^28707720 is an apocalyptic number.

28707720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28707720 is an abundant number, since it is smaller than the sum of its proper divisors (57415800).

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

28707720 is a wasteful number, since it uses less digits than its factorization.

28707720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239245 (or 239241 counting only the distinct ones).

The product of its (nonzero) digits is 10976, while the sum is 33.

The square root of 28707720 is about 5357.9585664691. The cubic root of 28707720 is about 306.1960382503.

The spelling of 28707720 in words is "twenty-eight million, seven hundred seven thousand, seven hundred twenty".