28715661 has 32 divisors (see below), whose sum is σ = 47819520. Its totient is φ = 16898112.

The previous prime is 28715653. The next prime is 28715677. The reversal of 28715661 is 16651782.

28715661 is a `hidden beast` number, since 28 + 71 + 566 + 1 = 666.

It is not a de Polignac number, because 28715661 - 2³ = 28715653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28715681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6295 + ... + 9851.

It is an arithmetic number, because the mean of its divisors is an integer number (1494360).

Almost surely, 2^28715661 is an apocalyptic number.

It is an amenable number.

28715661 is a deficient number, since it is larger than the sum of its proper divisors (19103859).

28715661 is a wasteful number, since it uses less digits than its factorization.

28715661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3602 (or 3596 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 28715661 is about 5358.6995623938. The cubic root of 28715661 is about 306.2242685031.

The spelling of 28715661 in words is "twenty-eight million, seven hundred fifteen thousand, six hundred sixty-one".