20161138520761 has 4 divisors (see below), whose sum is σ = 23041301166592. Its totient is φ = 17280975874932.

The previous prime is 20161138520753. The next prime is 20161138520791. The reversal of 20161138520761 is 16702583116102.

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 not a de Polignac number, because 20161138520761 - 2³ = 20161138520753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20161138520701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1440081322905 + ... + 1440081322918.

It is an arithmetic number, because the mean of its divisors is an integer number (5760325291648).

Almost surely, 2^{20161138520761} is an apocalyptic number.

It is an amenable number.

20161138520761 is a deficient number, since it is larger than the sum of its proper divisors (2880162645831).

20161138520761 is an equidigital number, since it uses as much as digits as its factorization.

20161138520761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2880162645830.

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

The spelling of 20161138520761 in words is "twenty trillion, one hundred sixty-one billion, one hundred thirty-eight million, five hundred twenty thousand, seven hundred sixty-one".