691424 has 48 divisors (see below), whose sum is σ = 1524096. Its totient is φ = 307200.

The previous prime is 691409. The next prime is 691433. The reversal of 691424 is 424196.

It is a junction number, because it is equal to n+sod(n) for n = 691393 and 691402.

It is a congruent number.

It is an unprimeable number.

691424 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16844 + ... + 16884.

It is an arithmetic number, because the mean of its divisors is an integer number (31752).

2⁶⁹¹⁴²⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 691424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (762048).

691424 is an abundant number, since it is smaller than the sum of its proper divisors (832672).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

691424 is a wasteful number, since it uses less digits than its factorization.

691424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99 (or 91 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 691424 is about 831.5190917832. The cubic root of 691424 is about 88.4263061286.

The spelling of 691424 in words is "six hundred ninety-one thousand, four hundred twenty-four".