681511968206 has 4 divisors (see below), whose sum is σ = 1022267952312. Its totient is φ = 340755984102.

The previous prime is 681511968199. The next prime is 681511968229. The reversal of 681511968206 is 602869115186.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170377992050 + ... + 170377992053.

It is an arithmetic number, because the mean of its divisors is an integer number (255566988078).

Almost surely, 2^681511968206 is an apocalyptic number.

681511968206 is a deficient number, since it is larger than the sum of its proper divisors (340755984106).

681511968206 is a wasteful number, since it uses less digits than its factorization.

681511968206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340755984105.

The product of its (nonzero) digits is 1244160, while the sum is 53.

The spelling of 681511968206 in words is "six hundred eighty-one billion, five hundred eleven million, nine hundred sixty-eight thousand, two hundred six".