688712649 has 8 divisors (see below), whose sum is σ = 918856512. Its totient is φ = 458855280.

The previous prime is 688712623. The next prime is 688712657. The reversal of 688712649 is 946217886.

688712649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 688712649 - 2⁵ = 688712617 is a prime.

It is a super-2 number, since 2×688712649² = 948650225785194402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (688712659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65949 + ... + 75674.

It is an arithmetic number, because the mean of its divisors is an integer number (114857064).

Almost surely, 2^688712649 is an apocalyptic number.

It is an amenable number.

688712649 is a deficient number, since it is larger than the sum of its proper divisors (230143863).

688712649 is a wasteful number, since it uses less digits than its factorization.

688712649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143247.

The product of its digits is 1161216, while the sum is 51.

The square root of 688712649 is about 26243.3353253736. The cubic root of 688712649 is about 883.1056970170.

The spelling of 688712649 in words is "six hundred eighty-eight million, seven hundred twelve thousand, six hundred forty-nine".