20413531324561 has 8 divisors (see below), whose sum is σ = 20748991789800. Its totient is φ = 20078097066240.

The previous prime is 20413531324507. The next prime is 20413531324567. The reversal of 20413531324561 is 16542313531402.

It can be written as a sum of positive squares in 4 ways, for example, as 1984841416336 + 18428689908225 = 1408844^2 + 4292865^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20413531324561 - 2⁹ = 20413531324049 is a prime.

It is a super-2 number, since 2×20413531324561² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20413531324567) 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, 4977976 + ... + 8099833.

It is an arithmetic number, because the mean of its divisors is an integer number (2593623973725).

Almost surely, 2^{20413531324561} is an apocalyptic number.

It is an amenable number.

20413531324561 is a deficient number, since it is larger than the sum of its proper divisors (335460465239).

20413531324561 is a wasteful number, since it uses less digits than its factorization.

20413531324561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13103459.

The product of its (nonzero) digits is 259200, while the sum is 40.

Adding to 20413531324561 its reverse (16542313531402), we get a palindrome (36955844855963).

The spelling of 20413531324561 in words is "twenty trillion, four hundred thirteen billion, five hundred thirty-one million, three hundred twenty-four thousand, five hundred sixty-one".