16680506749 has 2 divisors, whose sum is σ = 16680506750. Its totient is φ = 16680506748.

The previous prime is 16680506741. The next prime is 16680506813. The reversal of 16680506749 is 94760508661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15386665849 + 1293840900 = 124043^2 + 35970^2 .

It is a cyclic number.

It is not a de Polignac number, because 16680506749 - 2³ = 16680506741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16680506696 and 16680506705.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16680506741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8340253374 + 8340253375.

It is an arithmetic number, because the mean of its divisors is an integer number (8340253375).

Almost surely, 2^16680506749 is an apocalyptic number.

It is an amenable number.

16680506749 is a deficient number, since it is larger than the sum of its proper divisors (1).

16680506749 is an equidigital number, since it uses as much as digits as its factorization.

16680506749 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 52.

The spelling of 16680506749 in words is "sixteen billion, six hundred eighty million, five hundred six thousand, seven hundred forty-nine".