20751311744661 has 16 divisors (see below), whose sum is σ = 28257323745024. Its totient is φ = 13539758337024.

The previous prime is 20751311744651. The next prime is 20751311744693. The reversal of 20751311744661 is 16644711315702.

It is not a de Polignac number, because 20751311744661 - 2²⁹ = 20750774873749 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20751311744661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20751311744621) 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 15 ways as a sum of consecutive naturals, for example, 20496805 + ... + 21485381.

It is an arithmetic number, because the mean of its divisors is an integer number (1766082734064).

Almost surely, 2^{20751311744661} is an apocalyptic number.

It is an amenable number.

20751311744661 is a deficient number, since it is larger than the sum of its proper divisors (7506012000363).

20751311744661 is a wasteful number, since it uses less digits than its factorization.

20751311744661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1137500.

The product of its (nonzero) digits is 846720, while the sum is 48.

The spelling of 20751311744661 in words is "twenty trillion, seven hundred fifty-one billion, three hundred eleven million, seven hundred forty-four thousand, six hundred sixty-one".