68909440 has 32 divisors (see below), whose sum is σ = 164738160. Its totient is φ = 27563520.

The previous prime is 68909437. The next prime is 68909459. The reversal of 68909440 is 4490986.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×68909440² = 9497021842227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 68909393 and 68909402.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 53196 + ... + 54475.

Almost surely, 2^68909440 is an apocalyptic number.

It is an amenable number.

68909440 is an abundant number, since it is smaller than the sum of its proper divisors (95828720).

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

68909440 is a wasteful number, since it uses less digits than its factorization.

68909440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107690 (or 107678 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 68909440 is about 8301.1710017322. The cubic root of 68909440 is about 409.9770758549.

The spelling of 68909440 in words is "sixty-eight million, nine hundred nine thousand, four hundred forty".