28505280561 has 8 divisors (see below), whose sum is σ = 39317628480. Its totient is φ = 18348226512.

The previous prime is 28505280497. The next prime is 28505280563. The reversal of 28505280561 is 16508250582.

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

It is not a de Polignac number, because 28505280561 - 2⁶ = 28505280497 is a prime.

It is a super-2 number, since 2×28505280561² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28505280563) 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, 163823365 + ... + 163823538.

It is an arithmetic number, because the mean of its divisors is an integer number (4914703560).

Almost surely, 2^28505280561 is an apocalyptic number.

It is an amenable number.

28505280561 is a deficient number, since it is larger than the sum of its proper divisors (10812347919).

28505280561 is a wasteful number, since it uses less digits than its factorization.

28505280561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327646935.

The product of its (nonzero) digits is 192000, while the sum is 42.

The spelling of 28505280561 in words is "twenty-eight billion, five hundred five million, two hundred eighty thousand, five hundred sixty-one".