1669956749 has 2 divisors, whose sum is σ = 1669956750. Its totient is φ = 1669956748.

The previous prime is 1669956737. The next prime is 1669956781. The reversal of 1669956749 is 9476599661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1538051524 + 131905225 = 39218^2 + 11485^2 .

It is an emirp because it is prime and its reverse (9476599661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1669956749 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1669956691 and 1669956700.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1669953749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834978374 + 834978375.

It is an arithmetic number, because the mean of its divisors is an integer number (834978375).

Almost surely, 2^1669956749 is an apocalyptic number.

It is an amenable number.

1669956749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669956749 is an equidigital number, since it uses as much as digits as its factorization.

1669956749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22044960, while the sum is 62.

The square root of 1669956749 is about 40865.1042944956. The cubic root of 1669956749 is about 1186.4107534858.

The spelling of 1669956749 in words is "one billion, six hundred sixty-nine million, nine hundred fifty-six thousand, seven hundred forty-nine".