1000051000561 has 4 divisors (see below), whose sum is σ = 1021328681472. Its totient is φ = 978773319652.

The previous prime is 1000051000549. The next prime is 1000051000603. The reversal of 1000051000561 is 1650001500001.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1000051000561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1000051001561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10638840385 + ... + 10638840478.

It is an arithmetic number, because the mean of its divisors is an integer number (255332170368).

Almost surely, 2^{1000051000561} is an apocalyptic number.

It is an amenable number.

1000051000561 is a deficient number, since it is larger than the sum of its proper divisors (21277680911).

1000051000561 is an equidigital number, since it uses as much as digits as its factorization.

1000051000561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21277680910.

The product of its (nonzero) digits is 150, while the sum is 19.

Adding to 1000051000561 its reverse (1650001500001), we get a palindrome (2650052500562).

The spelling of 1000051000561 in words is "one trillion, fifty-one million, five hundred sixty-one", and thus it is an aban number.