20777725111081 has 9 divisors (see below), whose sum is σ = 20816904040023. Its totient is φ = 20738619807120.

The previous prime is 20777725111063. The next prime is 20777725111093. The reversal of 20777725111081 is 18011152777702.

The square root of 20777725111081 is 4558259.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 3424501992681 + 17353223118400 = 1850541^2 + 4165720^2 .

It is not a de Polignac number, because 20777725111081 - 2⁷ = 20777725110953 is a prime.

It is a super-3 number, since 3×20777725111081³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20777725111021) 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 8 ways as a sum of consecutive naturals, for example, 2593645366 + ... + 2593653376.

Almost surely, 2^{20777725111081} is an apocalyptic number.

20777725111081 is the 4558259-th square number.

20777725111081 is the 2279130-th centered octagonal number.

It is an amenable number.

20777725111081 is a deficient number, since it is larger than the sum of its proper divisors (39178928942).

20777725111081 is an frugal number, since it uses more digits than its factorization.

20777725111081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17160 (or 8580 counting only the distinct ones).

The product of its (nonzero) digits is 384160, while the sum is 49.

Adding to 20777725111081 its reverse (18011152777702), we get a palindrome (38788877888783).

The spelling of 20777725111081 in words is "twenty trillion, seven hundred seventy-seven billion, seven hundred twenty-five million, one hundred eleven thousand, eighty-one".