691328443 has 16 divisors (see below), whose sum is σ = 790171200. Its totient is φ = 599187456.

The previous prime is 691328399. The next prime is 691328459. The reversal of 691328443 is 344823196.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-691328443 is a prime.

It is a super-2 number, since 2×691328443² = 955870032201608498, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 691328396 and 691328405.

It is not an unprimeable number, because it can be changed into a prime (691328483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95746 + ... + 102712.

It is an arithmetic number, because the mean of its divisors is an integer number (49385700).

Almost surely, 2^691328443 is an apocalyptic number.

691328443 is a deficient number, since it is larger than the sum of its proper divisors (98842757).

691328443 is a wasteful number, since it uses less digits than its factorization.

691328443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7446.

The product of its digits is 124416, while the sum is 40.

The square root of 691328443 is about 26293.1253942927. The cubic root of 691328443 is about 884.2223234180. Note that the first 3 decimals are identical.

The spelling of 691328443 in words is "six hundred ninety-one million, three hundred twenty-eight thousand, four hundred forty-three".