681223640 has 32 divisors (see below), whose sum is σ = 1565369280. Its totient is φ = 266691072.

The previous prime is 681223633. The next prime is 681223709. The reversal of 681223640 is 46322186.

It is a junction number, because it is equal to n+sod(n) for n = 681223597 and 681223606.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 179297 + ... + 183056.

It is an arithmetic number, because the mean of its divisors is an integer number (48917790).

Almost surely, 2^681223640 is an apocalyptic number.

It is an amenable number.

681223640 is an abundant number, since it is smaller than the sum of its proper divisors (884145640).

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

681223640 is a wasteful number, since it uses less digits than its factorization.

681223640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362411 (or 362407 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 681223640 is about 26100.2613013740. The cubic root of 681223640 is about 879.8930827404.

The spelling of 681223640 in words is "six hundred eighty-one million, two hundred twenty-three thousand, six hundred forty".