66540972 has 12 divisors (see below), whose sum is σ = 155262296. Its totient is φ = 22180320.

The previous prime is 66540961. The next prime is 66540977. The reversal of 66540972 is 27904566.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 66540972.

It is not an unprimeable number, because it can be changed into a prime (66540977) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2772529 + ... + 2772552.

Almost surely, 2^66540972 is an apocalyptic number.

It is an amenable number.

66540972 is an abundant number, since it is smaller than the sum of its proper divisors (88721324).

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

66540972 is a wasteful number, since it uses less digits than its factorization.

66540972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5545088 (or 5545086 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 39.

The square root of 66540972 is about 8157.2649828236. The cubic root of 66540972 is about 405.2251392634.

The spelling of 66540972 in words is "sixty-six million, five hundred forty thousand, nine hundred seventy-two".