691030372891 has 2 divisors, whose sum is σ = 691030372892. Its totient is φ = 691030372890.

The previous prime is 691030372867. The next prime is 691030372897. The reversal of 691030372891 is 198273030196.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691030372891 - 2⁹ = 691030372379 is a prime.

It is not a weakly prime, because it can be changed into another prime (691030372897) 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, 345515186445 + 345515186446.

It is an arithmetic number, because the mean of its divisors is an integer number (345515186446).

Almost surely, 2^691030372891 is an apocalyptic number.

691030372891 is a deficient number, since it is larger than the sum of its proper divisors (1).

691030372891 is an equidigital number, since it uses as much as digits as its factorization.

691030372891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 489888, while the sum is 49.

The spelling of 691030372891 in words is "six hundred ninety-one billion, thirty million, three hundred seventy-two thousand, eight hundred ninety-one".