68157440 has 84 divisors (see below), whose sum is σ = 176160684. Its totient is φ = 25165824.

The previous prime is 68157433. The next prime is 68157461. The reversal of 68157440 is 4475186.

68157440 is nontrivially palindromic in base 15.

It can be written as a sum of positive squares in 2 ways, for example, as 16777216 + 51380224 = 4096^2 + 7168^2 .

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 68157440.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (2) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5242874 + ... + 5242886.

It is an arithmetic number, because the mean of its divisors is an integer number (2097151).

Almost surely, 2^68157440 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 68157440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88080342).

68157440 is an abundant number, since it is smaller than the sum of its proper divisors (108003244).

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

68157440 is an frugal number, since it uses more digits than its factorization.

68157440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 68157440 is about 8255.7519342577. The cubic root of 68157440 is about 408.4802751270.

The spelling of 68157440 in words is "sixty-eight million, one hundred fifty-seven thousand, four hundred forty".