68663640 has 64 divisors (see below), whose sum is σ = 208627200. Its totient is φ = 18076032.

The previous prime is 68663627. The next prime is 68663657. The reversal of 68663640 is 4636686.

68663640 = T₃₈₁ + T₃₈₂ + ... + T₇₇₅.

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 15 ways as a sum of consecutive naturals, for example, 5859 + ... + 13101.

It is an arithmetic number, because the mean of its divisors is an integer number (3259800).

Almost surely, 2^68663640 is an apocalyptic number.

68663640 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 68663640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104313600).

68663640 is an abundant number, since it is smaller than the sum of its proper divisors (139963560).

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

68663640 is a wasteful number, since it uses less digits than its factorization.

68663640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7336 (or 7332 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 39.

The square root of 68663640 is about 8286.3526355086. The cubic root of 68663640 is about 409.4890323125.

The spelling of 68663640 in words is "sixty-eight million, six hundred sixty-three thousand, six hundred forty".