28725780 has 24 divisors (see below), whose sum is σ = 80432352. Its totient is φ = 7660192.

The previous prime is 28725779. The next prime is 28725791. The reversal of 28725780 is 8752782.

It is a congruent 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, 239322 + ... + 239441.

It is an arithmetic number, because the mean of its divisors is an integer number (3351348).

Almost surely, 2^28725780 is an apocalyptic number.

28725780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28725780 is an abundant number, since it is smaller than the sum of its proper divisors (51706572).

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

28725780 is a wasteful number, since it uses less digits than its factorization.

28725780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478775 (or 478773 counting only the distinct ones).

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

The square root of 28725780 is about 5359.6436448704. The cubic root of 28725780 is about 306.2602340048.

The spelling of 28725780 in words is "twenty-eight million, seven hundred twenty-five thousand, seven hundred eighty".