68405140 has 12 divisors (see below), whose sum is σ = 143650836. Its totient is φ = 27362048.

The previous prime is 68405137. The next prime is 68405147. The reversal of 68405140 is 4150486.

It can be written as a sum of positive squares in 2 ways, for example, as 49168144 + 19236996 = 7012^2 + 4386^2 .

It is a junction number, because it is equal to n+sod(n) for n = 68405099 and 68405108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68405147) 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, 1710109 + ... + 1710148.

It is an arithmetic number, because the mean of its divisors is an integer number (11970903).

Almost surely, 2^68405140 is an apocalyptic number.

It is an amenable number.

68405140 is an abundant number, since it is smaller than the sum of its proper divisors (75245696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

68405140 is a wasteful number, since it uses less digits than its factorization.

68405140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3420266 (or 3420264 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 68405140 is about 8270.7399910770. The cubic root of 68405140 is about 408.9745143462.

The spelling of 68405140 in words is "sixty-eight million, four hundred five thousand, one hundred forty".