20024536561 has 4 divisors (see below), whose sum is σ = 20110479012. Its totient is φ = 19938594112.

The previous prime is 20024536549. The next prime is 20024536579. The reversal of 20024536561 is 16563542002.

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 11442366961 + 8582169600 = 106969^2 + 92640^2 .

It is a cyclic number.

It is not a de Polignac number, because 20024536561 - 2¹¹ = 20024534513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20024536061) 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, 42970876 + ... + 42971341.

It is an arithmetic number, because the mean of its divisors is an integer number (5027619753).

Almost surely, 2^20024536561 is an apocalyptic number.

It is an amenable number.

20024536561 is a deficient number, since it is larger than the sum of its proper divisors (85942451).

20024536561 is an equidigital number, since it uses as much as digits as its factorization.

20024536561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85942450.

The product of its (nonzero) digits is 43200, while the sum is 34.

The spelling of 20024536561 in words is "twenty billion, twenty-four million, five hundred thirty-six thousand, five hundred sixty-one".