687539939522 has 6 divisors (see below), whose sum is σ = 1031311668243. Its totient is φ = 343769383442.

The previous prime is 687539939519. The next prime is 687539939587. The reversal of 687539939522 is 225939935786.

It can be written as a sum of positive squares in only one way, i.e., 343769969761 + 343769969761 = 586319^2 + 586319^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=586319.

It is a super-3 number, since 3×687539939522³ (a number of 36 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 879479 + ... + 1465797.

Almost surely, 2^687539939522 is an apocalyptic number.

687539939522 is a deficient number, since it is larger than the sum of its proper divisors (343771728721).

687539939522 is an frugal number, since it uses more digits than its factorization.

687539939522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1172640 (or 586321 counting only the distinct ones).

The product of its digits is 220449600, while the sum is 68.

The spelling of 687539939522 in words is "six hundred eighty-seven billion, five hundred thirty-nine million, nine hundred thirty-nine thousand, five hundred twenty-two".