688020101 has 2 divisors, whose sum is σ = 688020102. Its totient is φ = 688020100.

The previous prime is 688020061. The next prime is 688020131. The reversal of 688020101 is 101020886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 682567876 + 5452225 = 26126^2 + 2335^2 .

It is a cyclic number.

It is not a de Polignac number, because 688020101 - 2¹⁴ = 688003717 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688020131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344010050 + 344010051.

It is an arithmetic number, because the mean of its divisors is an integer number (344010051).

Almost surely, 2^688020101 is an apocalyptic number.

It is an amenable number.

688020101 is a deficient number, since it is larger than the sum of its proper divisors (1).

688020101 is an equidigital number, since it uses as much as digits as its factorization.

688020101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 688020101 is about 26230.1372661296. The cubic root of 688020101 is about 882.8095898770.

Adding to 688020101 its reverse (101020886), we get a palindrome (789040987).

The spelling of 688020101 in words is "six hundred eighty-eight million, twenty thousand, one hundred one".