66356980 has 12 divisors (see below), whose sum is σ = 139349700. Its totient is φ = 26542784.

The previous prime is 66356977. The next prime is 66356981. The reversal of 66356980 is 8965366.

It can be written as a sum of positive squares in 2 ways, for example, as 19324816 + 47032164 = 4396^2 + 6858^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66356981) 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, 1658905 + ... + 1658944.

It is an arithmetic number, because the mean of its divisors is an integer number (11612475).

Almost surely, 2^66356980 is an apocalyptic number.

It is an amenable number.

66356980 is an abundant number, since it is smaller than the sum of its proper divisors (72992720).

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

66356980 is a wasteful number, since it uses less digits than its factorization.

66356980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3317858 (or 3317856 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 43.

The square root of 66356980 is about 8145.9793763549. The cubic root of 66356980 is about 404.8512993697.

It can be divided in two parts, 66 and 356980, that multiplied together give a triangular number (23560680 = T₆₈₆₄).

The spelling of 66356980 in words is "sixty-six million, three hundred fifty-six thousand, nine hundred eighty".