685281861 has 24 divisors (see below), whose sum is σ = 1117078560. Its totient is φ = 400999200.

The previous prime is 685281859. The next prime is 685281889. The reversal of 685281861 is 168182586.

685281861 is a `hidden beast` number, since 68 + 528 + 1 + 8 + 61 = 666.

It is not a de Polignac number, because 685281861 - 2¹ = 685281859 is a prime.

It is a super-2 number, since 2×685281861² = 939222458031246642, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685289861) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 116475 + ... + 122216.

It is an arithmetic number, because the mean of its divisors is an integer number (46544940).

Almost surely, 2^685281861 is an apocalyptic number.

It is an amenable number.

685281861 is a deficient number, since it is larger than the sum of its proper divisors (431796699).

685281861 is a wasteful number, since it uses less digits than its factorization.

685281861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238737 (or 238734 counting only the distinct ones).

The product of its digits is 184320, while the sum is 45.

The square root of 685281861 is about 26177.8887804192. Note that the first 3 decimals coincide. The cubic root of 685281861 is about 881.6368729006.

The spelling of 685281861 in words is "six hundred eighty-five million, two hundred eighty-one thousand, eight hundred sixty-one".