68390391 has 4 divisors (see below), whose sum is σ = 91187192. Its totient is φ = 45593592.

The previous prime is 68390353. The next prime is 68390401. The reversal of 68390391 is 19309386.

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

It is not a de Polignac number, because 68390391 - 2¹⁰ = 68389367 is a prime.

It is a super-2 number, since 2×68390391² = 9354491162265762, 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 (68390321) 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, 11398396 + ... + 11398401.

It is an arithmetic number, because the mean of its divisors is an integer number (22796798).

Almost surely, 2^68390391 is an apocalyptic number.

68390391 is a deficient number, since it is larger than the sum of its proper divisors (22796801).

68390391 is a wasteful number, since it uses less digits than its factorization.

68390391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22796800.

The product of its (nonzero) digits is 34992, while the sum is 39.

The square root of 68390391 is about 8269.8483057430. The cubic root of 68390391 is about 408.9451189008.

The spelling of 68390391 in words is "sixty-eight million, three hundred ninety thousand, three hundred ninety-one".