20043733756661 has 2 divisors, whose sum is σ = 20043733756662. Its totient is φ = 20043733756660.

The previous prime is 20043733756643. The next prime is 20043733756663. The reversal of 20043733756661 is 16665733734002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15706906681636 + 4336827075025 = 3963194^2 + 2082505^2 .

It is a cyclic number.

It is not a de Polignac number, because 20043733756661 - 2⁶ = 20043733756597 is a prime.

Together with 20043733756663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20043733756663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10021866878330 + 10021866878331.

It is an arithmetic number, because the mean of its divisors is an integer number (10021866878331).

Almost surely, 2^{20043733756661} is an apocalyptic number.

It is an amenable number.

20043733756661 is a deficient number, since it is larger than the sum of its proper divisors (1).

20043733756661 is an equidigital number, since it uses as much as digits as its factorization.

20043733756661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11430720, while the sum is 53.

The spelling of 20043733756661 in words is "twenty trillion, forty-three billion, seven hundred thirty-three million, seven hundred fifty-six thousand, six hundred sixty-one".