2161138520761 has 16 divisors (see below), whose sum is σ = 2433752064000. Its totient is φ = 1901220973200.

The previous prime is 2161138520741. The next prime is 2161138520773. The reversal of 2161138520761 is 1670258311612.

It is a cyclic number.

It is not a de Polignac number, because 2161138520761 - 2¹⁹ = 2161137996473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2161138520731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9841440 + ... + 10058638.

It is an arithmetic number, because the mean of its divisors is an integer number (152109504000).

Almost surely, 2^{2161138520761} is an apocalyptic number.

It is an amenable number.

2161138520761 is a deficient number, since it is larger than the sum of its proper divisors (272613543239).

2161138520761 is a wasteful number, since it uses less digits than its factorization.

2161138520761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246420.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 2161138520761 in words is "two trillion, one hundred sixty-one billion, one hundred thirty-eight million, five hundred twenty thousand, seven hundred sixty-one".