688640053 has 2 divisors, whose sum is σ = 688640054. Its totient is φ = 688640052.

The previous prime is 688640039. The next prime is 688640083. The reversal of 688640053 is 350046886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 685549489 + 3090564 = 26183^2 + 1758^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688640053 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 688639988 and 688640015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688640023) 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 as a sum of consecutive naturals, namely, 344320026 + 344320027.

It is an arithmetic number, because the mean of its divisors is an integer number (344320027).

Almost surely, 2^688640053 is an apocalyptic number.

It is an amenable number.

688640053 is a deficient number, since it is larger than the sum of its proper divisors (1).

688640053 is an equidigital number, since it uses as much as digits as its factorization.

688640053 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 688640053 is about 26241.9521568042. The cubic root of 688640053 is about 883.0746670493.

The spelling of 688640053 in words is "six hundred eighty-eight million, six hundred forty thousand, fifty-three".