690671491 has 2 divisors, whose sum is σ = 690671492. Its totient is φ = 690671490.

The previous prime is 690671479. The next prime is 690671543. The reversal of 690671491 is 194176096.

It is a happy number.

690671491 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 is a cyclic number.

It is not a de Polignac number, because 690671491 - 2⁵ = 690671459 is a prime.

It is not a weakly prime, because it can be changed into another prime (690671591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345335745 + 345335746.

It is an arithmetic number, because the mean of its divisors is an integer number (345335746).

Almost surely, 2^690671491 is an apocalyptic number.

690671491 is a deficient number, since it is larger than the sum of its proper divisors (1).

690671491 is an equidigital number, since it uses as much as digits as its factorization.

690671491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 43.

The square root of 690671491 is about 26280.6295776947. The cubic root of 690671491 is about 883.9421499205.

The spelling of 690671491 in words is "six hundred ninety million, six hundred seventy-one thousand, four hundred ninety-one".