686637644 has 48 divisors (see below), whose sum is σ = 1506011136. Its totient is φ = 266112000.

The previous prime is 686637593. The next prime is 686637659. The reversal of 686637644 is 446736686.

It is a junction number, because it is equal to n+sod(n) for n = 686637592 and 686637601.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53669 + ... + 65219.

It is an arithmetic number, because the mean of its divisors is an integer number (31375232).

Almost surely, 2^686637644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686637644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (753005568).

686637644 is an abundant number, since it is smaller than the sum of its proper divisors (819373492).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686637644 is a wasteful number, since it uses less digits than its factorization.

686637644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11766 (or 11764 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 50.

The square root of 686637644 is about 26203.7715605979. The cubic root of 686637644 is about 882.2179091813.

The spelling of 686637644 in words is "six hundred eighty-six million, six hundred thirty-seven thousand, six hundred forty-four".