66718920 has 64 divisors (see below), whose sum is σ = 200704320. Its totient is φ = 17743104.

The previous prime is 66718919. The next prime is 66718957. The reversal of 66718920 is 2981766.

66718920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 73107 + ... + 74013.

It is an arithmetic number, because the mean of its divisors is an integer number (3136005).

Almost surely, 2^66718920 is an apocalyptic number.

66718920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66718920 is an abundant number, since it is smaller than the sum of its proper divisors (133985400).

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

66718920 is a wasteful number, since it uses less digits than its factorization.

66718920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1534 (or 1530 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 39.

The square root of 66718920 is about 8168.1650326129. The cubic root of 66718920 is about 405.5860438148.

The spelling of 66718920 in words is "sixty-six million, seven hundred eighteen thousand, nine hundred twenty".