68640686 has 8 divisors (see below), whose sum is σ = 103164840. Its totient is φ = 34252408.

The previous prime is 68640653. The next prime is 68640701. The reversal of 68640686 is 68604686.

It is a sphenic number, since it is the product of 3 distinct 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 in 3 ways as a sum of consecutive naturals, for example, 32696 + ... + 34731.

It is an arithmetic number, because the mean of its divisors is an integer number (12895605).

Almost surely, 2^68640686 is an apocalyptic number.

68640686 is a deficient number, since it is larger than the sum of its proper divisors (34524154).

68640686 is a wasteful number, since it uses less digits than its factorization.

68640686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67938.

The product of its (nonzero) digits is 331776, while the sum is 44.

The square root of 68640686 is about 8284.9674712699. The cubic root of 68640686 is about 409.4433970057.

The spelling of 68640686 in words is "sixty-eight million, six hundred forty thousand, six hundred eighty-six".