68707781 has 8 divisors (see below), whose sum is σ = 72727200. Its totient is φ = 64728720.

The previous prime is 68707747. The next prime is 68707789. The reversal of 68707781 is 18770786.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68707781 is a prime.

It is a super-2 number, since 2×68707781² = 9441518339887922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68707789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6551 + ... + 13428.

It is an arithmetic number, because the mean of its divisors is an integer number (9090900).

Almost surely, 2^68707781 is an apocalyptic number.

It is an amenable number.

68707781 is a deficient number, since it is larger than the sum of its proper divisors (4019419).

68707781 is a wasteful number, since it uses less digits than its factorization.

68707781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20179.

The product of its (nonzero) digits is 131712, while the sum is 44.

The square root of 68707781 is about 8289.0156834210. The cubic root of 68707781 is about 409.5767613419.

The spelling of 68707781 in words is "sixty-eight million, seven hundred seven thousand, seven hundred eighty-one".