68640016 has 40 divisors (see below), whose sum is σ = 141386040. Its totient is φ = 32169984.

The previous prime is 68640001. The next prime is 68640023. The reversal of 68640016 is 61004686.

It can be written as a sum of positive squares in 4 ways, for example, as 14470416 + 54169600 = 3804^2 + 7360^2 .

It is a super-2 number, since 2×68640016² = 9422903592960512, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 68640016.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110940 + ... + 111556.

It is an arithmetic number, because the mean of its divisors is an integer number (3534651).

Almost surely, 2^68640016 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 68640016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70693020).

68640016 is an abundant number, since it is smaller than the sum of its proper divisors (72746024).

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

68640016 is a wasteful number, since it uses less digits than its factorization.

68640016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051 (or 1045 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 68640016 is about 8284.9270364922. The cubic root of 68640016 is about 409.4420648125.

The spelling of 68640016 in words is "sixty-eight million, six hundred forty thousand, sixteen".