688647953 has 4 divisors (see below), whose sum is σ = 787026240. Its totient is φ = 590269668.

The previous prime is 688647943. The next prime is 688648021. The reversal of 688647953 is 359746886.

688647953 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 359746886 = 2 ⋅179873443.

It is a cyclic number.

It is not a de Polignac number, because 688647953 - 2⁴ = 688647937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (688647943) 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, 49189133 + ... + 49189146.

It is an arithmetic number, because the mean of its divisors is an integer number (196756560).

Almost surely, 2^688647953 is an apocalyptic number.

It is an amenable number.

688647953 is a deficient number, since it is larger than the sum of its proper divisors (98378287).

688647953 is an equidigital number, since it uses as much as digits as its factorization.

688647953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98378286.

The product of its digits is 8709120, while the sum is 56.

The square root of 688647953 is about 26242.1026787108. The cubic root of 688647953 is about 883.0780438803.

The spelling of 688647953 in words is "six hundred eighty-eight million, six hundred forty-seven thousand, nine hundred fifty-three".