67784640 has 336 divisors, whose sum is σ = 275197824. Its totient is φ = 13977600.

The previous prime is 67784579. The next prime is 67784653. The reversal of 67784640 is 4648776.

It is a tau number, because it is divible by the number of its divisors (336).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 67784592 and 67784601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 517375 + ... + 517505.

Almost surely, 2^67784640 is an apocalyptic number.

67784640 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 67784640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137598912).

67784640 is an abundant number, since it is smaller than the sum of its proper divisors (207413184).

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

67784640 is a wasteful number, since it uses less digits than its factorization.

67784640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176 (or 159 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 42.

The square root of 67784640 is about 8233.1427778218. The cubic root of 67784640 is about 407.7341597732.

The spelling of 67784640 in words is "sixty-seven million, seven hundred eighty-four thousand, six hundred forty".