66717420 has 144 divisors (see below), whose sum is σ = 237178368. Its totient is φ = 13856640.

The previous prime is 66717397. The next prime is 66717433. The reversal of 66717420 is 2471766.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31309 + ... + 33371.

It is an arithmetic number, because the mean of its divisors is an integer number (1647072).

Almost surely, 2^66717420 is an apocalyptic number.

66717420 is a gapful number since it is divisible by the number (60) 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 66717420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118589184).

66717420 is an abundant number, since it is smaller than the sum of its proper divisors (170460948).

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

66717420 is a wasteful number, since it uses less digits than its factorization.

66717420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2100 (or 2091 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 33.

The square root of 66717420 is about 8168.0732122086. The cubic root of 66717420 is about 405.5830042791.

The spelling of 66717420 in words is "sixty-six million, seven hundred seventeen thousand, four hundred twenty".