686545091 has 2 divisors, whose sum is σ = 686545092. Its totient is φ = 686545090.

The previous prime is 686545073. The next prime is 686545099. The reversal of 686545091 is 190545686.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 686545091 - 2²⁶ = 619436227 is a prime.

It is not a weakly prime, because it can be changed into another prime (686545099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343272545 + 343272546.

It is an arithmetic number, because the mean of its divisors is an integer number (343272546).

Almost surely, 2^686545091 is an apocalyptic number.

686545091 is a deficient number, since it is larger than the sum of its proper divisors (1).

686545091 is an equidigital number, since it uses as much as digits as its factorization.

686545091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 259200, while the sum is 44.

The square root of 686545091 is about 26202.0054766806. The cubic root of 686545091 is about 882.1782688733.

The spelling of 686545091 in words is "six hundred eighty-six million, five hundred forty-five thousand, ninety-one".