686811337508881 has 4 divisors (see below), whose sum is σ = 739642978855732. Its totient is φ = 633979696162032.

The previous prime is 686811337508873. The next prime is 686811337508911. The reversal of 686811337508881 is 188805733118686.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 418419952659856 + 268391384849025 = 20455316^2 + 16382655^2 .

It is a cyclic number.

It is not a de Polignac number, because 686811337508881 - 2³ = 686811337508873 is a prime.

It is a super-2 number, since 2×686811337508881² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686811337508861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26415820673406 + ... + 26415820673431.

It is an arithmetic number, because the mean of its divisors is an integer number (184910744713933).

Almost surely, 2^{686811337508881} is an apocalyptic number.

It is an amenable number.

686811337508881 is a deficient number, since it is larger than the sum of its proper divisors (52831641346851).

686811337508881 is a wasteful number, since it uses less digits than its factorization.

686811337508881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52831641346850.

The product of its (nonzero) digits is 371589120, while the sum is 73.

The spelling of 686811337508881 in words is "six hundred eighty-six trillion, eight hundred eleven billion, three hundred thirty-seven million, five hundred eight thousand, eight hundred eighty-one".