681813906 has 16 divisors (see below), whose sum is σ = 1371795264. Its totient is φ = 225910064.

The previous prime is 681813901. The next prime is 681813931. The reversal of 681813906 is 609318186.

It is not an unprimeable number, because it can be changed into a prime (681813901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 339225 + ... + 341228.

It is an arithmetic number, because the mean of its divisors is an integer number (85737204).

Almost surely, 2^681813906 is an apocalyptic number.

681813906 is an abundant number, since it is smaller than the sum of its proper divisors (689981358).

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

681813906 is a wasteful number, since it uses less digits than its factorization.

681813906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680625.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 681813906 is about 26111.5665175416. The cubic root of 681813906 is about 880.1471456766.

The spelling of 681813906 in words is "six hundred eighty-one million, eight hundred thirteen thousand, nine hundred six".