691001 has 2 divisors, whose sum is σ = 691002. Its totient is φ = 691000.

The previous prime is 690997. The next prime is 691037. The reversal of 691001 is 100196.

691001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 511225 + 179776 = 715^2 + 424^2 .

It is a cyclic number.

It is not a de Polignac number, because 691001 - 2² = 690997 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (691051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345500 + 345501.

It is an arithmetic number, because the mean of its divisors is an integer number (345501).

2⁶⁹¹⁰⁰¹ is an apocalyptic number.

It is an amenable number.

691001 is a deficient number, since it is larger than the sum of its proper divisors (1).

691001 is an equidigital number, since it uses as much as digits as its factorization.

691001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 691001 is about 831.2646991182. The cubic root of 691001 is about 88.4082699415.

Adding to 691001 its reverse (100196), we get a palindrome (791197).

The spelling of 691001 in words is "six hundred ninety-one thousand, one".