691486189 has 2 divisors, whose sum is σ = 691486190. Its totient is φ = 691486188.

The previous prime is 691486141. The next prime is 691486193. The reversal of 691486189 is 981684196.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 613305225 + 78180964 = 24765^2 + 8842^2 .

It is a cyclic number.

It is not a de Polignac number, because 691486189 - 2¹¹ = 691484141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691486489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345743094 + 345743095.

It is an arithmetic number, because the mean of its divisors is an integer number (345743095).

Almost surely, 2^691486189 is an apocalyptic number.

It is an amenable number.

691486189 is a deficient number, since it is larger than the sum of its proper divisors (1).

691486189 is an equidigital number, since it uses as much as digits as its factorization.

691486189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 746496, while the sum is 52.

The square root of 691486189 is about 26296.1249806887. The cubic root of 691486189 is about 884.2895716888.

The spelling of 691486189 in words is "six hundred ninety-one million, four hundred eighty-six thousand, one hundred eighty-nine".