691066969 has 2 divisors, whose sum is σ = 691066970. Its totient is φ = 691066968.

The previous prime is 691066967. The next prime is 691066979. The reversal of 691066969 is 969660196.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 683299600 + 7767369 = 26140^2 + 2787^2 .

It is a cyclic number.

It is not a de Polignac number, because 691066969 - 2¹ = 691066967 is a prime.

It is a super-2 number, since 2×691066969² = 955147111285693922, which contains 22 as substring.

Together with 691066967, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (691066967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345533484 + 345533485.

It is an arithmetic number, because the mean of its divisors is an integer number (345533485).

Almost surely, 2^691066969 is an apocalyptic number.

It is an amenable number.

691066969 is a deficient number, since it is larger than the sum of its proper divisors (1).

691066969 is an equidigital number, since it uses as much as digits as its factorization.

691066969 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 944784, while the sum is 52.

The square root of 691066969 is about 26288.1526357407. The cubic root of 691066969 is about 884.1108326090.

The spelling of 691066969 in words is "six hundred ninety-one million, sixty-six thousand, nine hundred sixty-nine".