66523860 has 72 divisors (see below), whose sum is σ = 217318920. Its totient is φ = 16374528.

The previous prime is 66523859. The next prime is 66523867. The reversal of 66523860 is 6832566.

It can be written as a sum of positive squares in 4 ways, for example, as 133956 + 66389904 = 366^2 + 8148^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66523867) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11875 + ... + 16554.

Almost surely, 2^66523860 is an apocalyptic number.

66523860 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66523860 is an abundant number, since it is smaller than the sum of its proper divisors (150795060).

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

66523860 is a wasteful number, since it uses less digits than its factorization.

66523860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28457 (or 28452 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 66523860 is about 8156.2160344120. The cubic root of 66523860 is about 405.1903997294.

The spelling of 66523860 in words is "sixty-six million, five hundred twenty-three thousand, eight hundred sixty".