20304024641561 has 4 divisors (see below), whose sum is σ = 20582161965492. Its totient is φ = 20025887317632.

The previous prime is 20304024641533. The next prime is 20304024641567. The reversal of 20304024641561 is 16514642040302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14316998655961 + 5987025985600 = 3783781^2 + 2446840^2 .

It is a cyclic number.

It is not a de Polignac number, because 20304024641561 - 2⁴² = 15905978130457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20304024641567) 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, 139068661856 + ... + 139068662001.

It is an arithmetic number, because the mean of its divisors is an integer number (5145540491373).

Almost surely, 2^{20304024641561} is an apocalyptic number.

It is an amenable number.

20304024641561 is a deficient number, since it is larger than the sum of its proper divisors (278137323931).

20304024641561 is an equidigital number, since it uses as much as digits as its factorization.

20304024641561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278137323930.

The product of its (nonzero) digits is 138240, while the sum is 38.

Adding to 20304024641561 its reverse (16514642040302), we get a palindrome (36818666681863).

The spelling of 20304024641561 in words is "twenty trillion, three hundred four billion, twenty-four million, six hundred forty-one thousand, five hundred sixty-one".