68931540 has 96 divisors (see below), whose sum is σ = 216639360. Its totient is φ = 18194688.

The previous prime is 68931539. The next prime is 68931547. The reversal of 68931540 is 4513986.

68931540 is a `hidden beast` number, since 6 + 89 + 31 + 540 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 68931495 and 68931504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68931547) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 57184 + ... + 58376.

It is an arithmetic number, because the mean of its divisors is an integer number (2256660).

Almost surely, 2^68931540 is an apocalyptic number.

68931540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 68931540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108319680).

68931540 is an abundant number, since it is smaller than the sum of its proper divisors (147707820).

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

68931540 is a wasteful number, since it uses less digits than its factorization.

68931540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1318 (or 1310 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 68931540 is about 8302.5020325201. The cubic root of 68931540 is about 410.0208991925.

The spelling of 68931540 in words is "sixty-eight million, nine hundred thirty-one thousand, five hundred forty".