20611583777 has 2 divisors, whose sum is σ = 20611583778. Its totient is φ = 20611583776.

The previous prime is 20611583767. The next prime is 20611583807. The reversal of 20611583777 is 77738511602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18696733696 + 1914850081 = 136736^2 + 43759^2 .

It is a cyclic number.

It is not a de Polignac number, because 20611583777 - 2²⁰ = 20610535201 is a prime.

It is not a weakly prime, because it can be changed into another prime (20611583737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10305791888 + 10305791889.

It is an arithmetic number, because the mean of its divisors is an integer number (10305791889).

Almost surely, 2^20611583777 is an apocalyptic number.

It is an amenable number.

20611583777 is a deficient number, since it is larger than the sum of its proper divisors (1).

20611583777 is an equidigital number, since it uses as much as digits as its factorization.

20611583777 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 493920, while the sum is 47.

The spelling of 20611583777 in words is "twenty billion, six hundred eleven million, five hundred eighty-three thousand, seven hundred seventy-seven".