20110757561 has 2 divisors, whose sum is σ = 20110757562. Its totient is φ = 20110757560.

The previous prime is 20110757539. The next prime is 20110757609. The reversal of 20110757561 is 16575701102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20090227600 + 20529961 = 141740^2 + 4531^2 .

It is a cyclic number.

It is not a de Polignac number, because 20110757561 - 2¹⁴ = 20110741177 is a prime.

It is not a weakly prime, because it can be changed into another prime (20110757501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055378780 + 10055378781.

It is an arithmetic number, because the mean of its divisors is an integer number (10055378781).

Almost surely, 2^20110757561 is an apocalyptic number.

It is an amenable number.

20110757561 is a deficient number, since it is larger than the sum of its proper divisors (1).

20110757561 is an equidigital number, since it uses as much as digits as its factorization.

20110757561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14700, while the sum is 35.

The spelling of 20110757561 in words is "twenty billion, one hundred ten million, seven hundred fifty-seven thousand, five hundred sixty-one".