1561061270851 has 4 divisors (see below), whose sum is σ = 1584360692872. Its totient is φ = 1537761848832.

The previous prime is 1561061270827. The next prime is 1561061270891. The reversal of 1561061270851 is 1580721601651.

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

It is a cyclic number.

It is not a de Polignac number, because 1561061270851 - 2⁷ = 1561061270723 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1561061270798 and 1561061270807.

It is not an unprimeable number, because it can be changed into a prime (1561061270891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11649710910 + ... + 11649711043.

It is an arithmetic number, because the mean of its divisors is an integer number (396090173218).

Almost surely, 2^{1561061270851} is an apocalyptic number.

1561061270851 is a deficient number, since it is larger than the sum of its proper divisors (23299422021).

1561061270851 is an equidigital number, since it uses as much as digits as its factorization.

1561061270851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23299422020.

The product of its (nonzero) digits is 100800, while the sum is 43.

The spelling of 1561061270851 in words is "one trillion, five hundred sixty-one billion, sixty-one million, two hundred seventy thousand, eight hundred fifty-one".