685631956 has 36 divisors (see below), whose sum is σ = 1234525600. Its totient is φ = 333167328.

The previous prime is 685631951. The next prime is 685631957. The reversal of 685631956 is 659136586.

It is a happy number.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685631951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1561585 + ... + 1562023.

Almost surely, 2^685631956 is an apocalyptic number.

It is an amenable number.

685631956 is a deficient number, since it is larger than the sum of its proper divisors (548893644).

685631956 is a wasteful number, since it uses less digits than its factorization.

685631956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 688 (or 633 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 49.

The square root of 685631956 is about 26184.5747721822. The cubic root of 685631956 is about 881.7869834520.

The spelling of 685631956 in words is "six hundred eighty-five million, six hundred thirty-one thousand, nine hundred fifty-six".