688312031 has 16 divisors (see below), whose sum is σ = 836904960. Its totient is φ = 557930880.

The previous prime is 688311991. The next prime is 688312067. The reversal of 688312031 is 130213886.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688312031 is a prime.

It is a super-2 number, since 2×688312031² = 947546904038689922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688312081) 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 15 ways as a sum of consecutive naturals, for example, 93311 + ... + 100416.

It is an arithmetic number, because the mean of its divisors is an integer number (52306560).

Almost surely, 2^688312031 is an apocalyptic number.

688312031 is a deficient number, since it is larger than the sum of its proper divisors (148592929).

688312031 is a wasteful number, since it uses less digits than its factorization.

688312031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193774.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 688312031 is about 26235.7014581276. The cubic root of 688312031 is about 882.9344322381.

The spelling of 688312031 in words is "six hundred eighty-eight million, three hundred twelve thousand, thirty-one".