1669726901 has 2 divisors, whose sum is σ = 1669726902. Its totient is φ = 1669726900.

The previous prime is 1669726889. The next prime is 1669726907. The reversal of 1669726901 is 1096279661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1251319876 + 418407025 = 35374^2 + 20455^2 .

It is a cyclic number.

It is not a de Polignac number, because 1669726901 - 2¹⁴ = 1669710517 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1669726907) 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, 834863450 + 834863451.

It is an arithmetic number, because the mean of its divisors is an integer number (834863451).

Almost surely, 2^1669726901 is an apocalyptic number.

It is an amenable number.

1669726901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1669726901 is an equidigital number, since it uses as much as digits as its factorization.

1669726901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 244944, while the sum is 47.

The square root of 1669726901 is about 40862.2919205470. The cubic root of 1669726901 is about 1186.3563196109.

The spelling of 1669726901 in words is "one billion, six hundred sixty-nine million, seven hundred twenty-six thousand, nine hundred one".