16829778781 has 2 divisors, whose sum is σ = 16829778782. Its totient is φ = 16829778780.

The previous prime is 16829778767. The next prime is 16829778803. The reversal of 16829778781 is 18787792861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13067919225 + 3761859556 = 114315^2 + 61334^2 .

It is a cyclic number.

It is not a de Polignac number, because 16829778781 - 2²⁷ = 16695561053 is a prime.

It is a super-2 number, since 2×16829778781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16829778281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8414889390 + 8414889391.

It is an arithmetic number, because the mean of its divisors is an integer number (8414889391).

Almost surely, 2^16829778781 is an apocalyptic number.

It is an amenable number.

16829778781 is a deficient number, since it is larger than the sum of its proper divisors (1).

16829778781 is an equidigital number, since it uses as much as digits as its factorization.

16829778781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18966528, while the sum is 64.

The spelling of 16829778781 in words is "sixteen billion, eight hundred twenty-nine million, seven hundred seventy-eight thousand, seven hundred eighty-one".