687639321641 has 16 divisors (see below), whose sum is σ = 696224987136. Its totient is φ = 679124250000.

The previous prime is 687639321613. The next prime is 687639321661. The reversal of 687639321641 is 146123936786.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687639321641 is a prime.

It is a super-3 number, since 3×687639321641³ (a number of 36 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687639321601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14328476 + ... + 14376386.

It is an arithmetic number, because the mean of its divisors is an integer number (43514061696).

Almost surely, 2^687639321641 is an apocalyptic number.

It is an amenable number.

687639321641 is a deficient number, since it is larger than the sum of its proper divisors (8585665495).

687639321641 is a wasteful number, since it uses less digits than its factorization.

687639321641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48644.

The product of its digits is 7838208, while the sum is 56.

The spelling of 687639321641 in words is "six hundred eighty-seven billion, six hundred thirty-nine million, three hundred twenty-one thousand, six hundred forty-one".