28603516581 has 32 divisors (see below), whose sum is σ = 42558203520. Its totient is φ = 18986977152.

The previous prime is 28603516577. The next prime is 28603516589. The reversal of 28603516581 is 18561530682.

28603516581 is a `hidden beast` number, since 2 + 8 + 60 + 3 + 5 + 1 + 6 + 581 = 666.

It is not a de Polignac number, because 28603516581 - 2² = 28603516577 is a prime.

It is a super-2 number, since 2×28603516581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28603516589) 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 31 ways as a sum of consecutive naturals, for example, 12616210 + ... + 12618476.

It is an arithmetic number, because the mean of its divisors is an integer number (1329943860).

Almost surely, 2^28603516581 is an apocalyptic number.

It is an amenable number.

28603516581 is a deficient number, since it is larger than the sum of its proper divisors (13954686939).

28603516581 is a wasteful number, since it uses less digits than its factorization.

28603516581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4082 (or 4076 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 45.

The spelling of 28603516581 in words is "twenty-eight billion, six hundred three million, five hundred sixteen thousand, five hundred eighty-one".