68138889 has 16 divisors (see below), whose sum is σ = 111818112. Its totient is φ = 35941248.

The previous prime is 68138881. The next prime is 68138897. The reversal of 68138889 is 98883186.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (68138881) and next prime (68138897).

It is not a de Polignac number, because 68138889 - 2³ = 68138881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (68138881) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124524 + ... + 125069.

It is an arithmetic number, because the mean of its divisors is an integer number (6988632).

Almost surely, 2^68138889 is an apocalyptic number.

It is an amenable number.

68138889 is a deficient number, since it is larger than the sum of its proper divisors (43679223).

68138889 is a wasteful number, since it uses less digits than its factorization.

68138889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249616.

The product of its digits is 663552, while the sum is 51.

The square root of 68138889 is about 8254.6283380901. The cubic root of 68138889 is about 408.4432118943.

The spelling of 68138889 in words is "sixty-eight million, one hundred thirty-eight thousand, eight hundred eighty-nine".