688681131566 has 12 divisors (see below), whose sum is σ = 1097362150008. Its totient is φ = 324085238112.

The previous prime is 688681131451. The next prime is 688681131601. The reversal of 688681131566 is 665131186886.

It is a super-2 number, since 2×688681131566² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 595744346 + ... + 595745501.

It is an arithmetic number, because the mean of its divisors is an integer number (91446845834).

Almost surely, 2^688681131566 is an apocalyptic number.

688681131566 is a deficient number, since it is larger than the sum of its proper divisors (408681018442).

688681131566 is a wasteful number, since it uses less digits than its factorization.

688681131566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1191489883 (or 1191489866 counting only the distinct ones).

The product of its digits is 9953280, while the sum is 59.

The spelling of 688681131566 in words is "six hundred eighty-eight billion, six hundred eighty-one million, one hundred thirty-one thousand, five hundred sixty-six".