688148957 has 4 divisors (see below), whose sum is σ = 691102620. Its totient is φ = 685195296.

The previous prime is 688148947. The next prime is 688148959. The reversal of 688148957 is 759841886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 759841886 = 2 ⋅379920943.

It can be written as a sum of positive squares in 2 ways, for example, as 398162116 + 289986841 = 19954^2 + 17029^2 .

It is a cyclic number.

It is not a de Polignac number, because 688148957 - 2⁸ = 688148701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688148959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1476482 + ... + 1476947.

It is an arithmetic number, because the mean of its divisors is an integer number (172775655).

Almost surely, 2^688148957 is an apocalyptic number.

It is an amenable number.

688148957 is a deficient number, since it is larger than the sum of its proper divisors (2953663).

688148957 is a wasteful number, since it uses less digits than its factorization.

688148957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2953662.

The product of its digits is 3870720, while the sum is 56.

The square root of 688148957 is about 26232.5934097260. The cubic root of 688148957 is about 882.8646988345.

The spelling of 688148957 in words is "six hundred eighty-eight million, one hundred forty-eight thousand, nine hundred fifty-seven".