1671011516561 has 4 divisors (see below), whose sum is σ = 1673737473972. Its totient is φ = 1668285559152.

The previous prime is 1671011516509. The next prime is 1671011516563. The reversal of 1671011516561 is 1656151101761.

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 1502027536 + 1669509489025 = 38756^2 + 1292095^2 .

It is a cyclic number.

It is not a de Polignac number, because 1671011516561 - 2²⁶ = 1670944407697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1671011516563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1362977786 + ... + 1362979011.

It is an arithmetic number, because the mean of its divisors is an integer number (418434368493).

Almost surely, 2^{1671011516561} is an apocalyptic number.

It is an amenable number.

1671011516561 is a deficient number, since it is larger than the sum of its proper divisors (2725957411).

1671011516561 is an equidigital number, since it uses as much as digits as its factorization.

1671011516561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2725957410.

The product of its (nonzero) digits is 37800, while the sum is 41.

The spelling of 1671011516561 in words is "one trillion, six hundred seventy-one billion, eleven million, five hundred sixteen thousand, five hundred sixty-one".