66720143 has 4 divisors (see below), whose sum is σ = 76251600. Its totient is φ = 57188688.

The previous prime is 66720109. The next prime is 66720149. The reversal of 66720143 is 34102766.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34102766 = 2 ⋅17051383.

It is a cyclic number.

It is not a de Polignac number, because 66720143 - 2¹⁰ = 66719119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66720149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4765718 + ... + 4765731.

It is an arithmetic number, because the mean of its divisors is an integer number (19062900).

Almost surely, 2^66720143 is an apocalyptic number.

66720143 is a deficient number, since it is larger than the sum of its proper divisors (9531457).

66720143 is an equidigital number, since it uses as much as digits as its factorization.

66720143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9531456.

The product of its (nonzero) digits is 6048, while the sum is 29.

The square root of 66720143 is about 8168.2398960853. The cubic root of 66720143 is about 405.5885220159.

The spelling of 66720143 in words is "sixty-six million, seven hundred twenty thousand, one hundred forty-three".