68015540 has 24 divisors (see below), whose sum is σ = 143749032. Its totient is φ = 27031680.

The previous prime is 68015503. The next prime is 68015557. The reversal of 68015540 is 4551086.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 972196 + 67043344 = 986^2 + 8188^2 .

It is a super-2 number, since 2×68015540² = 9252227362983200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7691 + ... + 13970.

It is an arithmetic number, because the mean of its divisors is an integer number (5989543).

Almost surely, 2^68015540 is an apocalyptic number.

It is an amenable number.

68015540 is an abundant number, since it is smaller than the sum of its proper divisors (75733492).

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

68015540 is a wasteful number, since it uses less digits than its factorization.

68015540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21827 (or 21825 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 68015540 is about 8247.1534483117. The cubic root of 68015540 is about 408.1966004315.

The spelling of 68015540 in words is "sixty-eight million, fifteen thousand, five hundred forty".