68409040 has 80 divisors (see below), whose sum is σ = 183202560. Its totient is φ = 23270400.

The previous prime is 68409013. The next prime is 68409053. The reversal of 68409040 is 4090486.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 68408993 and 68409011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84156 + ... + 84964.

It is an arithmetic number, because the mean of its divisors is an integer number (2290032).

Almost surely, 2^68409040 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 68409040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91601280).

68409040 is an abundant number, since it is smaller than the sum of its proper divisors (114793520).

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

68409040 is a wasteful number, since it uses less digits than its factorization.

68409040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980 (or 974 counting only the distinct ones).

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

The square root of 68409040 is about 8270.9757586394. The cubic root of 68409040 is about 408.9822865219.

The spelling of 68409040 in words is "sixty-eight million, four hundred nine thousand, forty".