20001034561 has 4 divisors (see below), whose sum is σ = 20147027652. Its totient is φ = 19855041472.

The previous prime is 20001034457. The next prime is 20001034567. The reversal of 20001034561 is 16543010002.

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 12299919025 + 7701115536 = 110905^2 + 87756^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001034561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20001034567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72996340 + ... + 72996613.

It is an arithmetic number, because the mean of its divisors is an integer number (5036756913).

Almost surely, 2^20001034561 is an apocalyptic number.

It is an amenable number.

20001034561 is a deficient number, since it is larger than the sum of its proper divisors (145993091).

20001034561 is a wasteful number, since it uses less digits than its factorization.

20001034561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145993090.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 20001034561 its reverse (16543010002), we get a palindrome (36544044563).

The spelling of 20001034561 in words is "twenty billion, one million, thirty-four thousand, five hundred sixty-one".