691771032720 has 100 divisors (see below), whose sum is σ = 2402623303740. Its totient is φ = 184472273664.

The previous prime is 691771032709. The next prime is 691771032721. The reversal of 691771032720 is 27230177196.

It can be written as a sum of positive squares in 2 ways, for example, as 435536642304 + 256234390416 = 659952^2 + 506196^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (691771032721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 53370915 + ... + 53383874.

Almost surely, 2^691771032720 is an apocalyptic number.

691771032720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

691771032720 is an abundant number, since it is smaller than the sum of its proper divisors (1710852271020).

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

691771032720 is a wasteful number, since it uses less digits than its factorization.

691771032720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106754814 (or 106754799 counting only the distinct ones).

The product of its (nonzero) digits is 222264, while the sum is 45.

The spelling of 691771032720 in words is "six hundred ninety-one billion, seven hundred seventy-one million, thirty-two thousand, seven hundred twenty".