686811820031 has 4 divisors (see below), whose sum is σ = 708967040064. Its totient is φ = 664656600000.

The previous prime is 686811820027. The next prime is 686811820033. The reversal of 686811820031 is 130028118686.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 686811820031 - 2² = 686811820027 is a prime.

It is a super-2 number, since 2×686811820031² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686811820033) 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, 11077609970 + ... + 11077610031.

It is an arithmetic number, because the mean of its divisors is an integer number (177241760016).

Almost surely, 2^686811820031 is an apocalyptic number.

686811820031 is a deficient number, since it is larger than the sum of its proper divisors (22155220033).

686811820031 is a wasteful number, since it uses less digits than its factorization.

686811820031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22155220032.

The product of its (nonzero) digits is 110592, while the sum is 44.

The spelling of 686811820031 in words is "six hundred eighty-six billion, eight hundred eleven million, eight hundred twenty thousand, thirty-one".