691331536 has 20 divisors (see below), whose sum is σ = 1530805792. Its totient is φ = 296284896.

The previous prime is 691331533. The next prime is 691331561. The reversal of 691331536 is 635133196.

It is a junction number, because it is equal to n+sod(n) for n = 691331495 and 691331504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (691331533) 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 in 3 ways as a sum of consecutive naturals, for example, 3086190 + ... + 3086413.

Almost surely, 2^691331536 is an apocalyptic number.

It is an amenable number.

691331536 is an abundant number, since it is smaller than the sum of its proper divisors (839474256).

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

691331536 is a wasteful number, since it uses less digits than its factorization.

691331536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6172618 (or 6172612 counting only the distinct ones).

The product of its digits is 43740, while the sum is 37.

The square root of 691331536 is about 26293.1842118827. The cubic root of 691331536 is about 884.2236420848.

The spelling of 691331536 in words is "six hundred ninety-one million, three hundred thirty-one thousand, five hundred thirty-six".