28720758 has 32 divisors (see below), whose sum is σ = 63234432. Its totient is φ = 8624000.

The previous prime is 28720717. The next prime is 28720777. The reversal of 28720758 is 85702782.

It is a congruent number.

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, 5533 + ... + 9383.

It is an arithmetic number, because the mean of its divisors is an integer number (1976076).

Almost surely, 2^28720758 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28720758, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31617216).

28720758 is an abundant number, since it is smaller than the sum of its proper divisors (34513674).

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

28720758 is a wasteful number, since it uses less digits than its factorization.

28720758 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3980.

The product of its (nonzero) digits is 62720, while the sum is 39.

The square root of 28720758 is about 5359.1751230950. The cubic root of 28720758 is about 306.2423855944.

The spelling of 28720758 in words is "twenty-eight million, seven hundred twenty thousand, seven hundred fifty-eight".