28520861 has 8 divisors (see below), whose sum is σ = 28892160. Its totient is φ = 28151872.

The previous prime is 28520857. The next prime is 28520867. The reversal of 28520861 is 16802582.

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 28520861 - 2² = 28520857 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28520867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42950 + ... + 43608.

It is an arithmetic number, because the mean of its divisors is an integer number (3611520).

Almost surely, 2^28520861 is an apocalyptic number.

It is an amenable number.

28520861 is a deficient number, since it is larger than the sum of its proper divisors (371299).

28520861 is a wasteful number, since it uses less digits than its factorization.

28520861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155.

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 28520861 is about 5340.4925802776. The cubic root of 28520861 is about 305.5302466653.

The spelling of 28520861 in words is "twenty-eight million, five hundred twenty thousand, eight hundred sixty-one".