68421440 has 112 divisors (see below), whose sum is σ = 172547280. Its totient is φ = 25804800.

The previous prime is 68421401. The next prime is 68421461. The reversal of 68421440 is 4412486.

It can be written as a sum of positive squares in 8 ways, for example, as 4804864 + 63616576 = 2192^2 + 7976^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 677390 + ... + 677490.

Almost surely, 2^68421440 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 68421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86273640).

68421440 is an abundant number, since it is smaller than the sum of its proper divisors (104125840).

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

68421440 is a wasteful number, since it uses less digits than its factorization.

68421440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 29.

The square root of 68421440 is about 8271.7253339312. The cubic root of 68421440 is about 409.0069960923.

The spelling of 68421440 in words is "sixty-eight million, four hundred twenty-one thousand, four hundred forty".