66506500 has 24 divisors (see below), whose sum is σ = 145251288. Its totient is φ = 26602400.

The previous prime is 66506497. The next prime is 66506507. The reversal of 66506500 is 560566.

It can be written as a sum of positive squares in 4 ways, for example, as 2762244 + 63744256 = 1662^2 + 7984^2 .

It is a super-2 number, since 2×66506500² = 8846229084500000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66506507) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66007 + ... + 67006.

It is an arithmetic number, because the mean of its divisors is an integer number (6052137).

Almost surely, 2^66506500 is an apocalyptic number.

It is an amenable number.

66506500 is an abundant number, since it is smaller than the sum of its proper divisors (78744788).

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

66506500 is a wasteful number, since it uses less digits than its factorization.

66506500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133032 (or 133020 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 66506500 is about 8155.1517459824. The cubic root of 66506500 is about 405.1551506358.

The spelling of 66506500 in words is "sixty-six million, five hundred six thousand, five hundred".