688941645531 has 4 divisors (see below), whose sum is σ = 918588860712. Its totient is φ = 459294430352.

The previous prime is 688941645523. The next prime is 688941645541. The reversal of 688941645531 is 135546149886.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 688941645531 - 2³ = 688941645523 is a prime.

It is a super-2 number, since 2×688941645531² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (688941645541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114823607586 + ... + 114823607591.

It is an arithmetic number, because the mean of its divisors is an integer number (229647215178).

Almost surely, 2^688941645531 is an apocalyptic number.

688941645531 is a deficient number, since it is larger than the sum of its proper divisors (229647215181).

688941645531 is a wasteful number, since it uses less digits than its factorization.

688941645531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229647215180.

The product of its digits is 24883200, while the sum is 60.

The spelling of 688941645531 in words is "six hundred eighty-eight billion, nine hundred forty-one million, six hundred forty-five thousand, five hundred thirty-one".