688423213 has 2 divisors, whose sum is σ = 688423214. Its totient is φ = 688423212.

The previous prime is 688423193. The next prime is 688423217. The reversal of 688423213 is 312324886.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 667602244 + 20820969 = 25838^2 + 4563^2 .

It is a cyclic number.

It is not a de Polignac number, because 688423213 - 2²⁹ = 151552301 is a prime.

It is equal to p_35684218 and since 688423213 and 35684218 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688423217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344211606 + 344211607.

It is an arithmetic number, because the mean of its divisors is an integer number (344211607).

Almost surely, 2^688423213 is an apocalyptic number.

It is an amenable number.

688423213 is a deficient number, since it is larger than the sum of its proper divisors (1).

688423213 is an equidigital number, since it uses as much as digits as its factorization.

688423213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 55296, while the sum is 37.

The square root of 688423213 is about 26237.8202791314. The cubic root of 688423213 is about 882.9819693659.

The spelling of 688423213 in words is "six hundred eighty-eight million, four hundred twenty-three thousand, two hundred thirteen".