8281561 has 4 divisors (see below), whose sum is σ = 8290612. Its totient is φ = 8272512.

The previous prime is 8281547. The next prime is 8281571. The reversal of 8281561 is 1651828.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6734025 + 1547536 = 2595^2 + 1244^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8281561 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 (8281531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2976 + ... + 5041.

It is an arithmetic number, because the mean of its divisors is an integer number (2072653).

Almost surely, 2^8281561 is an apocalyptic number.

It is an amenable number.

8281561 is a deficient number, since it is larger than the sum of its proper divisors (9051).

8281561 is a wasteful number, since it uses less digits than its factorization.

8281561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9050.

The product of its digits is 3840, while the sum is 31.

The square root of 8281561 is about 2877.7701437050. The cubic root of 8281561 is about 202.3193409826.

The spelling of 8281561 in words is "eight million, two hundred eighty-one thousand, five hundred sixty-one".