66426720 has 48 divisors (see below), whose sum is σ = 209245680. Its totient is φ = 17713664.

The previous prime is 66426719. The next prime is 66426739. The reversal of 66426720 is 2762466.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68715 + ... + 69674.

It is an arithmetic number, because the mean of its divisors is an integer number (4359285).

Almost surely, 2^66426720 is an apocalyptic number.

66426720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66426720 is an abundant number, since it is smaller than the sum of its proper divisors (142818960).

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

66426720 is a wasteful number, since it uses less digits than its factorization.

66426720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138407 (or 138399 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 33.

The square root of 66426720 is about 8150.2588915936. The cubic root of 66426720 is about 404.9930802049.

The spelling of 66426720 in words is "sixty-six million, four hundred twenty-six thousand, seven hundred twenty".