67720043521 has 8 divisors (see below), whose sum is σ = 73610861184. Its totient is φ = 61926594960.

The previous prime is 67720043497. The next prime is 67720043543. The reversal of 67720043521 is 12534002776.

It is a happy number.

67720043521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 67720043521 - 2²¹ = 67717946369 is a prime.

It is a super-2 number, since 2×67720043521² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67720053521) 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, 24340825 + ... + 24343606.

It is an arithmetic number, because the mean of its divisors is an integer number (9201357648).

Almost surely, 2^67720043521 is an apocalyptic number.

It is an amenable number.

67720043521 is a deficient number, since it is larger than the sum of its proper divisors (5890817663).

67720043521 is a wasteful number, since it uses less digits than its factorization.

67720043521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48684551.

The product of its (nonzero) digits is 70560, while the sum is 37.

The spelling of 67720043521 in words is "sixty-seven billion, seven hundred twenty million, forty-three thousand, five hundred twenty-one".