685662544971 has 20 divisors (see below), whose sum is σ = 1035769897800. Its totient is φ = 451972309536.

The previous prime is 685662544967. The next prime is 685662544981. The reversal of 685662544971 is 179445266586.

685662544971 is a `hidden beast` number, since 6 + 8 + 566 + 25 + 4 + 49 + 7 + 1 = 666.

It is not a de Polignac number, because 685662544971 - 2² = 685662544967 is a prime.

It is a super-2 number, since 2×685662544971² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 685662544899 and 685662544908.

It is not an unprimeable number, because it can be changed into a prime (685662544901) 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 19 ways as a sum of consecutive naturals, for example, 47548801 + ... + 47563218.

It is an arithmetic number, because the mean of its divisors is an integer number (51788494890).

Almost surely, 2^685662544971 is an apocalyptic number.

685662544971 is a deficient number, since it is larger than the sum of its proper divisors (350107352829).

685662544971 is an equidigital number, since it uses as much as digits as its factorization.

685662544971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95112120 (or 95112111 counting only the distinct ones).

The product of its digits is 87091200, while the sum is 63.

The spelling of 685662544971 in words is "six hundred eighty-five billion, six hundred sixty-two million, five hundred forty-four thousand, nine hundred seventy-one".