68451840 has 120 divisors (see below), whose sum is σ = 237147768. Its totient is φ = 18247680.

The previous prime is 68451839. The next prime is 68451853. The reversal of 68451840 is 4815486.

It is a tau number, because it is divible by the number of its divisors (120).

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 = 68451795 and 68451804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21555 + ... + 24525.

Almost surely, 2^68451840 is an apocalyptic number.

68451840 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 68451840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118573884).

68451840 is an abundant number, since it is smaller than the sum of its proper divisors (168695928).

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

68451840 is a wasteful number, since it uses less digits than its factorization.

68451840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3000 (or 2981 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 68451840 is about 8273.5627150581. The cubic root of 68451840 is about 409.0675617652.

The spelling of 68451840 in words is "sixty-eight million, four hundred fifty-one thousand, eight hundred forty".