18977766777981 has 24 divisors (see below), whose sum is σ = 29938226681376. Its totient is φ = 11488651100640.

The previous prime is 18977766777967. The next prime is 18977766778021.

18977766777981 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18977766777981 - 2¹⁰ = 18977766776957 is a prime.

It is a super-2 number, since 2×18977766777981² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18977766777891 and 18977766777900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18977766777881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 108459930 + ... + 108634763.

It is an arithmetic number, because the mean of its divisors is an integer number (1247426111724).

Almost surely, 2^{18977766777981} is an apocalyptic number.

18977766777981 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18977766777981 is a deficient number, since it is larger than the sum of its proper divisors (10960459903395).

18977766777981 is a wasteful number, since it uses less digits than its factorization.

18977766777981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217095593 (or 217095590 counting only the distinct ones).

The product of its digits is 21956126976, while the sum is 90.

The spelling of 18977766777981 in words is "eighteen trillion, nine hundred seventy-seven billion, seven hundred sixty-six million, seven hundred seventy-seven thousand, nine hundred eighty-one".