16977568781 has 2 divisors, whose sum is σ = 16977568782. Its totient is φ = 16977568780.

The previous prime is 16977568757. The next prime is 16977568813. The reversal of 16977568781 is 18786577961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11206127881 + 5771440900 = 105859^2 + 75970^2 .

It is a cyclic number.

It is not a de Polignac number, because 16977568781 - 2¹⁰ = 16977567757 is a prime.

It is a super-3 number, since 3×16977568781³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16977564781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8488784390 + 8488784391.

It is an arithmetic number, because the mean of its divisors is an integer number (8488784391).

Almost surely, 2^16977568781 is an apocalyptic number.

It is an amenable number.

16977568781 is a deficient number, since it is larger than the sum of its proper divisors (1).

16977568781 is an equidigital number, since it uses as much as digits as its factorization.

16977568781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35562240, while the sum is 65.

The spelling of 16977568781 in words is "sixteen billion, nine hundred seventy-seven million, five hundred sixty-eight thousand, seven hundred eighty-one".