68391857 has 4 divisors (see below), whose sum is σ = 71365440. Its totient is φ = 65418276.

The previous prime is 68391853. The next prime is 68391863. The reversal of 68391857 is 75819386.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 68391857 - 2² = 68391853 is a prime.

It is a super-2 number, since 2×68391857² = 9354892207816898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68391853) 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, 1486757 + ... + 1486802.

It is an arithmetic number, because the mean of its divisors is an integer number (17841360).

Almost surely, 2^68391857 is an apocalyptic number.

It is an amenable number.

68391857 is a deficient number, since it is larger than the sum of its proper divisors (2973583).

68391857 is a wasteful number, since it uses less digits than its factorization.

68391857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2973582.

The product of its digits is 362880, while the sum is 47.

The square root of 68391857 is about 8269.9369405093. The cubic root of 68391857 is about 408.9480408964.

The spelling of 68391857 in words is "sixty-eight million, three hundred ninety-one thousand, eight hundred fifty-seven".