681631650 has 216 divisors, whose sum is σ = 2243807280. Its totient is φ = 147510720.

The previous prime is 681631619. The next prime is 681631679. The reversal of 681631650 is 56136186.

It is a happy number.

681631650 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 418137 + ... + 419763.

Almost surely, 2^681631650 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681631650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1121903640).

681631650 is an abundant number, since it is smaller than the sum of its proper divisors (1562175630).

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

681631650 is a wasteful number, since it uses less digits than its factorization.

681631650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1678 (or 1663 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 681631650 is about 26108.0763366434. The cubic root of 681631650 is about 880.0687145035.

The spelling of 681631650 in words is "six hundred eighty-one million, six hundred thirty-one thousand, six hundred fifty".