1561066161001 has 4 divisors (see below), whose sum is σ = 1586657409604. Its totient is φ = 1535474912400.

The previous prime is 1561066160999. The next prime is 1561066161023. The reversal of 1561066161001 is 1001616601651.

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 488008427776 + 1073057733225 = 698576^2 + 1035885^2 .

It is a cyclic number.

It is not a de Polignac number, because 1561066161001 - 2¹ = 1561066160999 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561066161091) 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, 12795624210 + ... + 12795624331.

It is an arithmetic number, because the mean of its divisors is an integer number (396664352401).

Almost surely, 2^{1561066161001} is an apocalyptic number.

It is an amenable number.

1561066161001 is a deficient number, since it is larger than the sum of its proper divisors (25591248603).

1561066161001 is an equidigital number, since it uses as much as digits as its factorization.

1561066161001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25591248602.

The product of its (nonzero) digits is 6480, while the sum is 34.

The spelling of 1561066161001 in words is "one trillion, five hundred sixty-one billion, sixty-six million, one hundred sixty-one thousand, one".