691406543 has 4 divisors (see below), whose sum is σ = 691494048. Its totient is φ = 691319040.

The previous prime is 691406533. The next prime is 691406563. The reversal of 691406543 is 345604196.

691406543 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 691406543 - 2⁶ = 691406479 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 691406497 and 691406506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691406533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30578 + ... + 48143.

It is an arithmetic number, because the mean of its divisors is an integer number (172873512).

Almost surely, 2^691406543 is an apocalyptic number.

691406543 is a deficient number, since it is larger than the sum of its proper divisors (87505).

691406543 is an equidigital number, since it uses as much as digits as its factorization.

691406543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87504.

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 691406543 is about 26294.6105314378. The cubic root of 691406543 is about 884.2556192963.

The spelling of 691406543 in words is "six hundred ninety-one million, four hundred six thousand, five hundred forty-three".