66540900 has 72 divisors (see below), whose sum is σ = 194050080. Its totient is φ = 17603840.

The previous prime is 66540899. The next prime is 66540913. The reversal of 66540900 is 904566.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40291 + ... + 41909.

It is an arithmetic number, because the mean of its divisors is an integer number (2695140).

Almost surely, 2^66540900 is an apocalyptic number.

66540900 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66540900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97025040).

66540900 is an abundant number, since it is smaller than the sum of its proper divisors (127509180).

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

66540900 is a wasteful number, since it uses less digits than its factorization.

66540900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1773 (or 1766 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 66540900 is about 8157.2605695785. The cubic root of 66540900 is about 405.2249931068.

The spelling of 66540900 in words is "sixty-six million, five hundred forty thousand, nine hundred".