681491650 has 24 divisors (see below), whose sum is σ = 1448657280. Its totient is φ = 233654160.

The previous prime is 681491623. The next prime is 681491731. The reversal of 681491650 is 56194186.

681491650 is digitally balanced in base 2, 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 11 ways as a sum of consecutive naturals, for example, 973210 + ... + 973909.

It is an arithmetic number, because the mean of its divisors is an integer number (60360720).

Almost surely, 2^681491650 is an apocalyptic number.

681491650 is an abundant number, since it is smaller than the sum of its proper divisors (767165630).

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

681491650 is a wasteful number, since it uses less digits than its factorization.

681491650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1947138 (or 1947133 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 681491650 is about 26105.3950362755. The cubic root of 681491650 is about 880.0084580799.

The spelling of 681491650 in words is "six hundred eighty-one million, four hundred ninety-one thousand, six hundred fifty".