1243691 has 2 divisors, whose sum is σ = 1243692. Its totient is φ = 1243690.

The previous prime is 1243673. The next prime is 1243709. The reversal of 1243691 is 1963421.

It is a balanced prime because it is at equal distance from previous prime (1243673) and next prime (1243709).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243691 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1243691.

It is not a weakly prime, because it can be changed into another prime (1243631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621845 + 621846.

It is an arithmetic number, because the mean of its divisors is an integer number (621846).

2^1243691 is an apocalyptic number.

1243691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243691 is an equidigital number, since it uses as much as digits as its factorization.

1243691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 26.

The square root of 1243691 is about 1115.2089490315. The cubic root of 1243691 is about 107.5401976945.

The spelling of 1243691 in words is "one million, two hundred forty-three thousand, six hundred ninety-one".