68139311 has 4 divisors (see below), whose sum is σ = 69980952. Its totient is φ = 66297672.

The previous prime is 68139307. The next prime is 68139359. The reversal of 68139311 is 11393186.

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

It is a cyclic number.

It is not a de Polignac number, because 68139311 - 2² = 68139307 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68139371) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 920765 + ... + 920838.

It is an arithmetic number, because the mean of its divisors is an integer number (17495238).

Almost surely, 2^68139311 is an apocalyptic number.

68139311 is a deficient number, since it is larger than the sum of its proper divisors (1841641).

68139311 is a wasteful number, since it uses less digits than its factorization.

68139311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1841640.

The product of its digits is 3888, while the sum is 32.

The square root of 68139311 is about 8254.6538994679. The cubic root of 68139311 is about 408.4440550872. Note that the first 3 decimals are identical.

The spelling of 68139311 in words is "sixty-eight million, one hundred thirty-nine thousand, three hundred eleven".