687697897 has 2 divisors, whose sum is σ = 687697898. Its totient is φ = 687697896.

The previous prime is 687697891. The next prime is 687697939. The reversal of 687697897 is 798796786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 563397696 + 124300201 = 23736^2 + 11149^2 .

It is a cyclic number.

It is not a de Polignac number, because 687697897 - 2²³ = 679309289 is a prime.

It is not a weakly prime, because it can be changed into another prime (687697891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343848948 + 343848949.

It is an arithmetic number, because the mean of its divisors is an integer number (343848949).

Almost surely, 2^687697897 is an apocalyptic number.

It is an amenable number.

687697897 is a deficient number, since it is larger than the sum of its proper divisors (1).

687697897 is an equidigital number, since it uses as much as digits as its factorization.

687697897 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64012032, while the sum is 67.

The square root of 687697897 is about 26223.9946804449. The cubic root of 687697897 is about 882.6717599915.

The spelling of 687697897 in words is "six hundred eighty-seven million, six hundred ninety-seven thousand, eight hundred ninety-seven".