1391669 has 2 divisors, whose sum is σ = 1391670. Its totient is φ = 1391668.

The previous prime is 1391653. The next prime is 1391701. The reversal of 1391669 is 9661931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1322500 + 69169 = 1150^2 + 263^2 .

It is a cyclic number.

It is not a de Polignac number, because 1391669 - 2⁴ = 1391653 is a prime.

It is a super-2 number, since 2×1391669² = 3873485211122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1391629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695834 + 695835.

It is an arithmetic number, because the mean of its divisors is an integer number (695835).

2^1391669 is an apocalyptic number.

It is an amenable number.

1391669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391669 is an equidigital number, since it uses as much as digits as its factorization.

1391669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 35.

The square root of 1391669 is about 1179.6902135730. The cubic root of 1391669 is about 111.6465526505.

The spelling of 1391669 in words is "one million, three hundred ninety-one thousand, six hundred sixty-nine".