687639321553 has 2 divisors, whose sum is σ = 687639321554. Its totient is φ = 687639321552.

The previous prime is 687639321539. The next prime is 687639321563. The reversal of 687639321553 is 355123936786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 475516438929 + 212122882624 = 689577^2 + 460568^2 .

It is a cyclic number.

It is not a de Polignac number, because 687639321553 - 2⁵ = 687639321521 is a prime.

It is not a weakly prime, because it can be changed into another prime (687639321563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343819660776 + 343819660777.

It is an arithmetic number, because the mean of its divisors is an integer number (343819660777).

Almost surely, 2^687639321553 is an apocalyptic number.

It is an amenable number.

687639321553 is a deficient number, since it is larger than the sum of its proper divisors (1).

687639321553 is an equidigital number, since it uses as much as digits as its factorization.

687639321553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24494400, while the sum is 58.

The spelling of 687639321553 in words is "six hundred eighty-seven billion, six hundred thirty-nine million, three hundred twenty-one thousand, five hundred fifty-three".