1006991 has 2 divisors, whose sum is σ = 1006992. Its totient is φ = 1006990.

The previous prime is 1006987. The next prime is 1007021. The reversal of 1006991 is 1996001.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1006991 - 2² = 1006987 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1006991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1006091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 503495 + 503496.

It is an arithmetic number, because the mean of its divisors is an integer number (503496).

2^1006991 is an apocalyptic number.

1006991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1006991 is an equidigital number, since it uses as much as digits as its factorization.

1006991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 1006991 is about 1003.4894120019. The cubic root of 1006991 is about 100.2324923873.

The spelling of 1006991 in words is "one million, six thousand, nine hundred ninety-one".