688565873 has 2 divisors, whose sum is σ = 688565874. Its totient is φ = 688565872.

The previous prime is 688565869. The next prime is 688565897. The reversal of 688565873 is 378565886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 535598449 + 152967424 = 23143^2 + 12368^2 .

It is a cyclic number.

It is not a de Polignac number, because 688565873 - 2² = 688565869 is a prime.

It is a super-2 number, since 2×688565873² = 948245922920504258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (688565863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344282936 + 344282937.

It is an arithmetic number, because the mean of its divisors is an integer number (344282937).

Almost surely, 2^688565873 is an apocalyptic number.

It is an amenable number.

688565873 is a deficient number, since it is larger than the sum of its proper divisors (1).

688565873 is an equidigital number, since it uses as much as digits as its factorization.

688565873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9676800, while the sum is 56.

The square root of 688565873 is about 26240.5387330367. The cubic root of 688565873 is about 883.0429577740.

The spelling of 688565873 in words is "six hundred eighty-eight million, five hundred sixty-five thousand, eight hundred seventy-three".