8005131621 has 6 divisors (see below), whose sum is σ = 11562967910. Its totient is φ = 5336754408.

The previous prime is 8005131613. The next prime is 8005131647. The reversal of 8005131621 is 1261315008.

8005131621 is a `hidden beast` number, since 8 + 0 + 0 + 5 + 1 + 31 + 621 = 666.

8005131621 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 4766383521 + 3238748100 = 69039^2 + 56910^2 .

It is not a de Polignac number, because 8005131621 - 2³ = 8005131613 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 (8005131671) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 444729526 + ... + 444729543.

Almost surely, 2^8005131621 is an apocalyptic number.

It is an amenable number.

8005131621 is a deficient number, since it is larger than the sum of its proper divisors (3557836289).

8005131621 is a wasteful number, since it uses less digits than its factorization.

8005131621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889459075 (or 889459072 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 8005131621 is about 89471.4011346643. The cubic root of 8005131621 is about 2000.4275436800.

Adding to 8005131621 its reverse (1261315008), we get a palindrome (9266446629).

The spelling of 8005131621 in words is "eight billion, five million, one hundred thirty-one thousand, six hundred twenty-one".