67721744 has 40 divisors (see below), whose sum is σ = 139553568. Its totient is φ = 31726080.

The previous prime is 67721743. The next prime is 67721747. The reversal of 67721744 is 44712776.

It is a super-2 number, since 2×67721744² = 9172469220803072, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 67721698 and 67721707.

It is not an unprimeable number, because it can be changed into a prime (67721741) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83099 + ... + 83909.

Almost surely, 2^67721744 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 67721744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69776784).

67721744 is an abundant number, since it is smaller than the sum of its proper divisors (71831824).

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

67721744 is a wasteful number, since it uses less digits than its factorization.

67721744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1143 (or 1137 counting only the distinct ones).

The product of its digits is 65856, while the sum is 38.

The square root of 67721744 is about 8229.3222078127. The cubic root of 67721744 is about 407.6080113145.

The spelling of 67721744 in words is "sixty-seven million, seven hundred twenty-one thousand, seven hundred forty-four".