68310781 has 8 divisors (see below), whose sum is σ = 85166784. Its totient is φ = 53229120.

The previous prime is 68310773. The next prime is 68310791. The reversal of 68310781 is 18701386.

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

It is not a de Polignac number, because 68310781 - 2³ = 68310773 is a prime.

It is a super-2 number, since 2×68310781² = 9332725601659922, 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 (68310761) 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, 443500 + ... + 443653.

It is an arithmetic number, because the mean of its divisors is an integer number (10645848).

Almost surely, 2^68310781 is an apocalyptic number.

It is an amenable number.

68310781 is a deficient number, since it is larger than the sum of its proper divisors (16856003).

68310781 is a wasteful number, since it uses less digits than its factorization.

68310781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 887171.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 68310781 is about 8265.0336357452. The cubic root of 68310781 is about 408.7863794397.

The spelling of 68310781 in words is "sixty-eight million, three hundred ten thousand, seven hundred eighty-one".