681568026 has 16 divisors (see below), whose sum is σ = 1366394400. Its totient is φ = 226646288.

The previous prime is 681567983. The next prime is 681568049. The reversal of 681568026 is 620865186.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 133041 + ... + 138068.

It is an arithmetic number, because the mean of its divisors is an integer number (85399650).

Almost surely, 2^681568026 is an apocalyptic number.

681568026 is an abundant number, since it is smaller than the sum of its proper divisors (684826374).

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

681568026 is a wasteful number, since it uses less digits than its factorization.

681568026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271533.

The product of its (nonzero) digits is 138240, while the sum is 42.

The square root of 681568026 is about 26106.8578346763. The cubic root of 681568026 is about 880.0413315642.

The spelling of 681568026 in words is "six hundred eighty-one million, five hundred sixty-eight thousand, twenty-six".