685661835381 has 16 divisors (see below), whose sum is σ = 966039797760. Its totient is φ = 431699027760.

The previous prime is 685661835371. The next prime is 685661835403. The reversal of 685661835381 is 183538166586.

It is not a de Polignac number, because 685661835381 - 2⁵ = 685661835349 is a prime.

It is a super-2 number, since 2×685661835381² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685661835371) 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, 62887765 + ... + 62898666.

It is an arithmetic number, because the mean of its divisors is an integer number (60377487360).

Almost surely, 2^685661835381 is an apocalyptic number.

It is an amenable number.

685661835381 is a deficient number, since it is larger than the sum of its proper divisors (280377962379).

685661835381 is a wasteful number, since it uses less digits than its factorization.

685661835381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125786536.

The product of its digits is 24883200, while the sum is 60.

The spelling of 685661835381 in words is "six hundred eighty-five billion, six hundred sixty-one million, eight hundred thirty-five thousand, three hundred eighty-one".