28295282287561 has 9 divisors (see below), whose sum is σ = 28724264980551. Its totient is φ = 27872613565632.

The previous prime is 28295282287553. The next prime is 28295282287667. The reversal of 28295282287561 is 16578228259282.

The square root of 28295282287561 is 5319331.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 18533756857225 + 9761525430336 = 4305085^2 + 3124344^2 .

It is not a de Polignac number, because 28295282287561 - 2³ = 28295282287553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (67).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28295282284561) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 356355481 + ... + 356434873.

It is an arithmetic number, because the mean of its divisors is an integer number (3191584997839).

Almost surely, 2^{28295282287561} is an apocalyptic number.

28295282287561 is the 5319331-st square number.

28295282287561 is the 2659666-th centered octagonal number.

It is an amenable number.

28295282287561 is a deficient number, since it is larger than the sum of its proper divisors (428982692990).

28295282287561 is an frugal number, since it uses more digits than its factorization.

28295282287561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158920 (or 79460 counting only the distinct ones).

The product of its digits is 154828800, while the sum is 67.

The spelling of 28295282287561 in words is "twenty-eight trillion, two hundred ninety-five billion, two hundred eighty-two million, two hundred eighty-seven thousand, five hundred sixty-one".