688891131 has 6 divisors (see below), whose sum is σ = 995064980. Its totient is φ = 459260748.

The previous prime is 688891129. The next prime is 688891163. The reversal of 688891131 is 131198886.

It is not a de Polignac number, because 688891131 - 2¹ = 688891129 is a prime.

It is a super-2 number, since 2×688891131² = 949141980740918322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688891121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 38271721 + ... + 38271738.

Almost surely, 2^688891131 is an apocalyptic number.

688891131 is a deficient number, since it is larger than the sum of its proper divisors (306173849).

688891131 is a wasteful number, since it uses less digits than its factorization.

688891131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76543465 (or 76543462 counting only the distinct ones).

The product of its digits is 82944, while the sum is 45.

The square root of 688891131 is about 26246.7356255973. The cubic root of 688891131 is about 883.1819769467.

The spelling of 688891131 in words is "six hundred eighty-eight million, eight hundred ninety-one thousand, one hundred thirty-one".