66957780 has 48 divisors (see below), whose sum is σ = 187838784. Its totient is φ = 17821440.

The previous prime is 66957773. The next prime is 66957823. The reversal of 66957780 is 8775966.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56595 + ... + 57765.

It is an arithmetic number, because the mean of its divisors is an integer number (3913308).

Almost surely, 2^66957780 is an apocalyptic number.

66957780 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66957780 is an abundant number, since it is smaller than the sum of its proper divisors (120881004).

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

66957780 is a wasteful number, since it uses less digits than its factorization.

66957780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2136 (or 2134 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 48.

The square root of 66957780 is about 8182.7733684858. The cubic root of 66957780 is about 406.0694794016.

The spelling of 66957780 in words is "sixty-six million, nine hundred fifty-seven thousand, seven hundred eighty".