691319440628 has 24 divisors (see below), whose sum is σ = 1220766454152. Its totient is φ = 342530284544.

The previous prime is 691319440597. The next prime is 691319440631. The reversal of 691319440628 is 826044913196.

691319440628 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 76807688164 + 614511752464 = 277142^2 + 783908^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 691319440628.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2076626 + ... + 2386422.

It is an arithmetic number, because the mean of its divisors is an integer number (50865268923).

Almost surely, 2^691319440628 is an apocalyptic number.

It is an amenable number.

691319440628 is a deficient number, since it is larger than the sum of its proper divisors (529447013524).

691319440628 is a wasteful number, since it uses less digits than its factorization.

691319440628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314851 (or 314849 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 53.

The spelling of 691319440628 in words is "six hundred ninety-one billion, three hundred nineteen million, four hundred forty thousand, six hundred twenty-eight".