691546917649 has 9 divisors (see below), whose sum is σ = 804459308457. Its totient is φ = 592749511284.

The previous prime is 691546917637. The next prime is 691546917679. The reversal of 691546917649 is 946719645196.

The square root of 691546917649 is 831593.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 691546917649 - 2⁷ = 691546917521 is a prime.

It is not an unprimeable number, because it can be changed into a prime (691546917679) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5761752 + ... + 5880550.

Almost surely, 2^691546917649 is an apocalyptic number.

691546917649 is the 831593-rd square number.

691546917649 is the 415797-th centered octagonal number.

It is an amenable number.

691546917649 is a deficient number, since it is larger than the sum of its proper divisors (112912390808).

691546917649 is an frugal number, since it uses more digits than its factorization.

691546917649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237612 (or 118806 counting only the distinct ones).

The product of its digits is 88179840, while the sum is 67.

The spelling of 691546917649 in words is "six hundred ninety-one billion, five hundred forty-six million, nine hundred seventeen thousand, six hundred forty-nine".