28720087 has 8 divisors (see below), whose sum is σ = 32060160. Its totient is φ = 25501560.

The previous prime is 28720073. The next prime is 28720091. The reversal of 28720087 is 78002782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28720087 - 2¹⁵ = 28687319 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28720037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29887 + ... + 30832.

It is an arithmetic number, because the mean of its divisors is an integer number (4007520).

Almost surely, 2^28720087 is an apocalyptic number.

28720087 is a deficient number, since it is larger than the sum of its proper divisors (3340073).

28720087 is a wasteful number, since it uses less digits than its factorization.

28720087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60773.

The product of its (nonzero) digits is 12544, while the sum is 34.

The square root of 28720087 is about 5359.1125198115. The cubic root of 28720087 is about 306.2400006731.

The spelling of 28720087 in words is "twenty-eight million, seven hundred twenty thousand, eighty-seven".