1291669 has 2 divisors, whose sum is σ = 1291670. Its totient is φ = 1291668.

The previous prime is 1291637. The next prime is 1291673. The reversal of 1291669 is 9661921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1238769 + 52900 = 1113^2 + 230^2 .

It is a cyclic number.

It is not a de Polignac number, because 1291669 - 2⁵ = 1291637 is a prime.

It is a super-2 number, since 2×1291669² = 3336817611122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645834 + 645835.

It is an arithmetic number, because the mean of its divisors is an integer number (645835).

2^1291669 is an apocalyptic number.

It is an amenable number.

1291669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291669 is an equidigital number, since it uses as much as digits as its factorization.

1291669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5832, while the sum is 34.

The square root of 1291669 is about 1136.5161679448. The cubic root of 1291669 is about 108.9056501956.

The spelling of 1291669 in words is "one million, two hundred ninety-one thousand, six hundred sixty-nine".