67721016 has 128 divisors (see below), whose sum is σ = 203212800. Its totient is φ = 18564480.

The previous prime is 67721011. The next prime is 67721021. The reversal of 67721016 is 61012776.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (67721011) and next prime (67721021).

It is a super-3 number, since 3×67721016³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (67721011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 115075 + ... + 115661.

It is an arithmetic number, because the mean of its divisors is an integer number (1587600).

Almost surely, 2^67721016 is an apocalyptic number.

67721016 is a gapful number since it is divisible by the number (66) 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 67721016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101606400).

67721016 is an abundant number, since it is smaller than the sum of its proper divisors (135491784).

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

67721016 is a wasteful number, since it uses less digits than its factorization.

67721016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649 (or 645 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 67721016 is about 8229.2779756185. The cubic root of 67721016 is about 407.6065507314.

The spelling of 67721016 in words is "sixty-seven million, seven hundred twenty-one thousand, sixteen".